Do you honestly believe that's how it would be? Do you.... 
More like.....
Explosion and missiles likes normal then slightly slowed torso movement only noticeable to the pilot of the damaged mech....roughly equivilant to moving up in weight class, ie medium to heavy....aggressor only notices slight improvement in ability to get out of weapons arc, easily countered by vets with pilot skill, crippling to noobs while they type "why torso move slower?"
Well, in this game if you lose a side torso in this game, you are good as dead in the next 30 seconds or so anyways. Same goes for the rear torso, unless you manage to turn around and back up to a wall.
Brings up some ideas and puzzlement as to how this whole crit system is gonna play out. I think I will start a new thread to not derail this one though.
Not a bad idea Victor, but it will really just make anyone losing a side torso as easy as pie, as they have to turn their legs to protect that damaged component.