OKW Anti tank: Cheap schu mines,the perfect anti tank mine,shreks on mainline infantry for cheap reinforce cost and great vet,the perfect AT squad,JP4,the best non doc TD hands down in the game,arguably the best TD period.
USF infantry: Hard countered by the new MG spam,but USF has always had the best infantry. from double bar rifles to M1919 paras/barfinders. If ostheer and OKW could not build suppression they would get rolled by usf infantry all day.
I still think that T-mines, Faust, dual shreks, pak 40s, and Stug is better than Volks shreks, puppchens, schu mines, and JPIV.
Infantry is debatable between soviets and USF. Paratroopers and pathfinders are kinda insane but so are Guards and shocks. I also consider the maxim a pseudo infantry unit because of its set up time and narrow arc. Riflemen are great early fans but falter late game.
IMO USF can put out the most anti infantry dps from its troops, and soviet infantry are very cheap and durable.