Their vet was the result of Relic buffing their survival from the curse of manpower bleed since the beginning of WFA. I would say they overbuffed them and toned it back afterwards.
Knowing how Relic has a thing for making some things a complete disaster, removing the veterancy would probably bring back the USF's notorious manpower bleed. So I suggest that the riflemen's survival vet doesn't get touched.
Maybe changing their accuracy or the weapon profile of the BARs and Bazookas would be a more reasonable approach.
I dont beleive there was much manpower bleed if there was now its gone due to new patch changes but still what they can do is either keep the recived accuracy buff but remove the weapon accruracy buff that they also get with vet 3 or just replace received accuracy with reduced refinforcment cost both ways u tone them down and they dont bleed.