I don't remove the FG-42. They spawn with 2 as usual. In fact, I even buff them a bit IMO. I just don't allow for four of them to be used, since that is where the balance issues start showing up.
They also become a 5-man squad.
Agreed on that. IMO the best way to put them in to the game is an elite VG replacement. Imagine the Falls 5 men 300MP aviable from T0 with 5 grenadier kar98s and have the option to upgrade to 2-3 FG42s as their upgrade.
(Maybe this can open the way of Pfusi being buffed and locked to 2-3 CP as elite infantry)