A foreword: While I've been enjoying the game... well, not since Early Access but definitely long before Expedition, I couldn't help but notice that combat skills are essential in anyone's walkthrough. Compared to other isometric (original Fallout) games, there is no other way to defeat Tchort, Shadowlith (Cognator is an exception) but through firepower or power of mind. Therefore, I've made my way thoughout all the caves and subway tunnels with pistols, sledgehammers, rifles, psi disciplines, fist weapons, knifes, swords, spears, grenades, crossbows, traps and the likes of them, heavy guns and grenade launchers included.
Thus, after analyzing each combat style, I've decided to start a discussion over which I would like to express my thought on matter of balance. Which is in imperfect state as of now.
(this topic is gonna be a longread, so, if you don't want to read... what are you doing here? You should already be able to read The Bible through in an hour
So, please, read the whole topic before starting yelling at the poor pipeworker)
Firstly, I'm going to range the weapons (not classes) in order:
1. LMG and Grenade Launchers, with my bae Fusion Cannon. Those weapons allow you to bruteforce everything that stands in your way, in a corner of the room, on another location and a zone above and below you. Even a 30% hit chance often turns out to be enough to kill an otherwise hard enemy with one burst. Grenade launchers, on other hand, completely outshine Frag and HE grenades. I literally dominated Depot A, Ironheads, Vanga and her crew, every Stalker nest, every industrial robot encounter... Even Tchort, while still proved to be one tough mass of psionic flesh, succumbed to Fusion Cannon (and GlaShaG). Overpowered weapons, so to speak.
2. Grenades and Shotguns. Those are versatile in most combat encounters. Grenades are somewhat essential, because you can save-load every combat situation to try and get the best output all over again, if your throwing skill is not the main one. Flashbangs and EMPs are much more important than their psi-counterparts. Why? Because, in this game, AoE reigns and prevails — over single target attacks. I'm gonna elaborate on that below. Way, way below
Anyway, most situations are easily resolved by a well-timed and well-placed grenade. Shotguns, on other hand, prove their versatility differently. While most enemies prefer to close the distance (narrow passages greatly suggest for them and the player to do so), shotguns see that as a win-win situation. With their tremendous close-range damage output, they are still able to grease and/or wound the enemy afar. And they can do that with a single shell or with burst as well. Overall reliable weapons.
3. Miniguns and Assault Rifles. Those are fairly balanced. Higher usefulness than average weapons but they also have downsides and requirements. Assault rifles, IMO, always were, and are, the balanced type of weapons. As for miniguns: those need to be bursted from a couple times over before they actually start the massacre. Along with their Intiative penalty, strength requirement, and ammo consumption, miniguns are fine. Still reliable weapons but require some tactic thinking.
4. Now for average weapons. Pistols and fist weapons. Now, pistols offer a wide range of variety... of themselves. I'm gonna give you one example: one can stun the enemy with Wasteland Hawk, bind them in palce with XAL, disperce their shields with Phase Gun and finish them off with Sonocaster. All in one fight. Gloves, fists and claws don't have many damage types but they have even better set of feats which allows them to dominate the melee. It would be wise to add some AoE weapons (grenades) or any psi discipline to pistols and melee but those are also fine on their own.
5. Less than average. SMG and knives/swords/spears/sledgehammers. Caltrops too. I'll be brief: SMGs are too weak to deal significant damage, being mostly stealth weapons in their design. Only one of their unique models (RRCh-42) have a special bonus, and, after refurbishing, Mini-Uzi. Also, SMGs are designed to work the best with commando-style tactic. Flashbangs and such. While pistols allow but a wide range of action, along with combining it with melee (some unique pistols have bonuses while used in melee range) or psi abilities (shower your enemies with heat, cold, and acid damage during one turn).
Right, there's also cold steel. Those are slightly better but they do require some real luck with RNG (fr some pipeworker hit me 5 times in a row with his crappy knife (147 dodge) but when I try to hit him with my Bone knife — 5 misses in a row with 60% hit chance. And it happens. Every. Other. Time!). Unarmed do have better bonuses and chances, so to speak. Just take a look at Carnifex and how he dominates any even slightly unsuitable build. Spears suffer from average AP cost, and overall mediocre... ness. Taht goes for Sledgehammers as well. Yes, there's Quake, Mindcracker, Lemurian Spear and Rust Maker (you can also coat your cold steel with some poison) but you actually have to life to see them. And then, you probably will be buff enough to live without them. Or for them to compliment your build but not define it. It just feels like a less successful brother of Fist weapons.
Caltrops aren't that bad, they're just helpful tools rather than weapons (even though they use throwing — a combat skill), therefore they are placed here.
5.5. Psi disciplines. Low quality on their own but fine if you master two or more. Those, after implementing psi reserves, are one of the weakest ways to resolve sticky sutiations with guns... mind blazing.
Pro: you always hit, with the exception of AoE abilities; you can inflict unique debuffs on some enemies; you can inflict buffs and debuffs alike without resorting to combat drugs and special throwing items.
Con: you have to "reload" your psi reserve, therefore you have to have a lot of usually rare "ammo" for it, therefore you can't rely on your psi abilities to kill each burrower spawn and rathound you come across; you have to resort to tactic every now and then; robots are immune to most effects of psi abilities, notably Thought Control ones; AoE effects are mainly metathermic, therefore you are forced to use it or resort to other AoE weapons; 8 abilties at a time aren't enough for most sutiations — spending psi inhalant each time you want to change one of more of your abilities seems rather excessive; all special and unique psi-related items never a direct bonus — only a trade-off. And their bonuses rarely outweight penalties.
Take Cognator's helmet, for instance. Oh wow, 3 more slots for psi abilities! I could use 11 in total and give the enemy hell! But wait, I can't see crap in it, I can't dodge and evade attacks, I never get first turn, and I get my ass beaten with criticals occuring 10% more otfen. Was that designed at a joke headwear?
Take Sergio's hat. Seems like a direct upgrade... if it wouldn't require to be in Motion and to have Motion on you, in some quantity. I do hope I don't need to explain downsides of Motion and the need to invest up to 150 skill points into Biology in order to craft it (because dead Sergio can't sell you Motion) and carry it around with you.
Take Psychophract Exoskeleton, also the HD's addition to armour department. Perennial energy draining just to negate Agility and movement speed penalties (your Dexterity is still crap, however); random bonus for one of two psi schools — others get severe penalty of increased psi cost; relatively high Strength requirement — when I'm a psionic, I invest into Will and Intelligence. I don't sink all points into Strength.
Regular Psi Headbands and Hypno Goggles are the most benign items for psionic. But for other armour it would be best to clad yourself in some regular vest or an overcoat. It's just plain sad. All in all, psi disciplines can compliment the build, but on their own they're relatively weak and clattered with unnecessary complications.
6. Sniper rifles, throwing knives, crossbows, and traps. That one is a difficult tier.
Sniper rifles suffer greatly. Most enemies, as I stated above, tend to close the distance between them and the player. Precision penalty and/or focus loss is the least downside of that. Relying on throwing nets and caltrops? Assault rifles, for instance, don't see that problem. Only Dragunov is semi-capable of fighting on its own. Also, high AP cost? Why have them sniper rifles if you can just pick up an LMG and deal even more damage with less precision but for cost of more ammo (the latter is never a problem to obtain)? Why have them sniper rifles if your average double-basrrel does even more damage but at close quarters? I can hardly see anyone dominating the DOMINATING with a restriction to sniper rifles only. But assault rifles or pistols? Never a problem.
Throwing knives suck. They just suck. They suck, okay? Frankly, I could never see them as weapon and I never pick them up. They cost nothing and grenades are much more useful if you invest in throwing. Even if you coat them in poison... you actually need to invest in Biology. Invest A LOT (60/70/150!). You need to hunt dangerous creatures to get your ingredients and extract some humour for your poison. And if you are able to hunt dangerous creatures, then why the hell you would need throwing knives in the first place? They obviously need major reworking and that is it. Yes, Shock Shurikens exist, and yes, they are good against robots. They still suck because of their higher-than-average AP cost and their Electricity damage does not scale with Throwing.
Crossbows suck for similar reasons. One would need to invest a lot of skill points in tons of skills, to be an effective fighter.
They have different combat skill for whatever reason (I guess Styg or whoever created crossbows wanted it to be unique. Well, they are, but it's not a good uniqueness). They have different bolts which could pass as a positive attribute but... not really. Pistols and psi abilities exist. And those are much easier to obtain and/or invest into. Speaking of — you have to either buy/pick up every bolt in your way or... well, you'll spend a crapload of points into Biology and Chemistry anyway. And don't forget about Stealth and Traps, because those are essential as well. 5 skills investment just for one weapon to be effective — too much hassle. But that's the problem of character skills, not the weapon itself.
Related to crossbows: traps. Caltrops are a tier higher because of the following: traps require to have Quick Tinkering in order to be used in combat; traps restrict you to move accordingly, in order to lure the enemy in your trap AND not get hit with it if it's a landmine; traps also require to invest a crapload of skill points in order to craft them. Even their detection can be (and often is) achieved with pure detection and not hybrid one. In other words: combat tools but worse than caltrops.