Add back the knock around feature when things get hit, but take it up a tier
If you hit the arms on an enemy they sway ruining the arm weapon aim (ie arms move), if you hit the torso, same thing but to a lesser effect (ie it's center mass so the knock around isn't as bad). But if you hit the legs, no knock effect. This plays into the fact we now know that arm and torso weapons' aim are independent of each other.
Take one further and allow legs to mount as much armor as a side torso section. This remove the problem of legs being a "better" target than a torso.
This makes it more strategic in shot selection. Sure the legger can take off the leg but if you target his arms, and lets say it's got a lot of weapons mounted in the arms (*cough* clan mechs make heavy use of arm weapon pods), you're going to ruin his strat by knock his arm aim off so only his torso weapons may hit the leg.
In short
- Target arm = arm weapon aim sway when hit with enough force, arms tend to not be able to mount as much armor as a torso.
- Target torso = lesser cockpit knock effect, obviously the main way to destroy mech when torso is breached
- Target legs = no knock effect, can now mount as much armor as a torso section.