I guess it's pretty much an alternative for STR 3 no dodge/Eva build. I think for sword, metal is usually better since it requires 7 STR anyways, and pistol with 5 str is kinda wasted stats, since they need both Dex and Per. Shield can't really works well enough, and Shield Arm, which helps a lot with shield, requires 8 STR at which point, SuperSteel should works at least similarly well.
Imo Iron Grip isn't worth it since it lowers damage output and spear guard works as good, or better than shield, especially when you could take Spear Guardian which makes block chance 100% with specialization. And it works much better alongside SS metal armor for more protection in general
It would be much better if RG shield also block ranged :/