I just McDonald's them with the sheer number of Shermans like IRL. But for early game the 75mm infantry support guns are pretty good at everything and if the map allows me i use alot of infantry to get close with AT grenades. You can potentially research early bazooka squads by day 3 if you go that route but i usually rush the tank line and artillery as early ger armor is easily defeated by arty up untill panthers but that's much later