There is no good counter play to vs mg spam as okw.
your first unit, which cant be count as a anti mg tool is the isg...which come mostly around minute 4. until this you are mostly helpless vs mg spam on most maps.
but isg is not good vs mgs. since it has no retreat, has not the range from pak howie and only 4models.
why USF got mortar, when the have nondoc early smoke? they even has super early reinforce and healing from the start....which means you can try your push much more often.
so yeah: give OKW some more tools vs early mg spam. kubel doesnt help this much, because get serios dmg from mg crew, when you try to flank it.
and one more sqaud near by nullify any kubel flank hard
isg is the best howitzer/mortar in this game according to its ACC and damage.
๊USF mortar is suck please try it yourself.
allies mg already have bad suppression rate especially Maxim.just use volk volk volk volk = win.
Honestly as OKW I just ran into MG in difference direction and win meanwhile if you use IS run into MG42 they will got suppressed in first burst and then pinned down.
I suggest you to go play as allies as until your rank > 500 and met with experienced OKW player. then try to spam MG and see what will happen.