Shreck blobs with elite infantry mixed in are one of the hardest things to beat currently as USF, but on open maps you have to make an equally strong force with either 1919lmg riflemen/RE or Airborne mixed with scots jacksons and HE shells shermans. 2 Shermans with he shells are very good deterrant against blobs but they have low HP to stick around for long against all the shrecks.
As Soviet just forget about conscripts, on open maps double or triple snipers work or maxim spam into shocks. Follow up with powerhouse IS-2, the broken isu or the mobile t3485s
On small maps stuka zu fuss is basically invincible, it has double HP of katysuha and pwerfer so a lot less vulnerable to m3guard drivebyes or a m20. your best bet is to counter with indirect fire a la b4 or priest. Dont bother with atguns or mgs on small maps i would say and try to secure as much as reliable axis support weapons as possible
