They should really give RE and pios sandbags.
RE don't need sandbags when they can already make much better cover. I mean feel free to add it but it feels a bit silly when tank traps are already the best green cover.
The same way you counter maxim strats?
Except you would be easily outnumbering .50 cals who are also 50% less durable?
You're like a typical woman.
You'll find a problem for every solution.
Maxim's have lower AoE suppression, smaller arc, and are supported by far less deadly infantry. A .50 cal in the USF HQ to start would make the kubel unusable (unless you made it much more durable) and make Urban maps a living hell for OKW.
Like maxim spam is already a huge hard to counter problem for OKW, but at least maxims lock you into a tier and don't come with the best basic infantry in the game.
The only way you could balance it would be to give OKW smoke to enable pushes, but it would need to be free or have a reduced cost due to OKW's munitions penalty.