You're really focused on armor penalty. Armor penalty only affects four things: Dodge, Evasion, Stealth, and move points. If you don't have Dodge or Evasion, aren't using Stealth at the moment, and have a way to get move points unaffected by armor penalty, then armor penalty has no effect on you at all. Sprint + psi haste is a lot of mobility for a short time, or a fair bit of mobility for a good while. Sledge juggernauts have been viable with capped ArPen + Sprint for years, and they're melee.