USF nades don't insta-kill mg crew either. And you don't have to move survived mg from burning building. USF had some problems dealing with well placed mgs.
If the Ostheer player is using a mg to backup another, the USF player should just ignore that area until he get pack howis. That's 520 mp guarding a small area of the map. A single mg in even the best position can be broken with 3 inf squads from different directions. Dear USF players: you can't have the whole map!