You're claiming falls are replacing volks as mainline in late game - I do not see that as a possibility due to their call-in and upkeep costs together with relative fragility and high reinforce cost.
You are talking about fixing an issue that does not exist.
not only in the late game. when volks get wiped in early mid game. can call in as soon as his mp can do. n completely replace the mainline inf volks.(1) can be go in the battle as soon as it made (2) these two are the main points.
n about fragility. it is yes about model number. but i know that falls have a good evasion rate even at 0vet. +reinforce cost be relative according to the play style tho. (1)get good cover. (2)retreat before model drop. (3)fight from long distance.
to sum what. yeah falls reinforcement is expensive 36 n needs 108 one to full squad but he can fight from long range n thats what he mainly does. get good cover n hide n shoot from far. so you can reduce the mp bleed. but see the rifles 28 for reinforcement(cheap?) and needs 112 one to full(???) and he have to hug the enemies in many situation to deal with.
+ dont forget how airbone costs