Pretty good way to illustrate the vast difference in power that lies between an AToW fight and a TW battlefield...
It's a matter of scale, you can carry larger, and more, weapons when you are based on a vehicle, rather than on yourself. BA exists in a scale that sits between the two. Large enough to carry a few weapons, but small ones on the vehicle scale and armor just enough to stop one large, or a couple medium weapon hits.
On the infantry scale? That 'piddling' machine gun or 'small' laser is an infantry support weapon that requires a small vehicle or several soldiers to move, and is often set up in a static position. Making a single suit, even the 'small' PA(L) a walking machine gun nest.
And battle armor's protection is roughly scaled to their armament. So you needs those multi-man crewed weapons, or other anti-tank/armor 'heavy' weapons, to have a decent chance of doing more than scratch the armor. But you can't carry the armor one does, so I can see why things get, messy, for PBIs. Which kinda fits how a single machine gun IS Standard BA squad/Elemental point can chew through an entire infantry platoon in TW, quickly and often with little loss in return.
In ATOW you carry a weapon, in TW weapon carries you. :thumbsup: