I played 2v2 where one sov just transition midway into 120mm, dushka, su85 and reinforce ht. Totally lock out a sector. Dushka with its high mobility gets to cap and defend. Su86 disable any AI tanks to clear dushka, and the 120mm to kill any ATG or capping infantry.
And you couldn't outflank one dushka that had basically no infantry support? even though the dushka has one of the narrowest cones of fire in the game? No wonder you lose Panthers to AECs, likewise, a single SU-85 with no infantry to snare for it means free real estate, just flank the bloody thing, it's turretless.
"oh, but he does have infantry, and I just haven't bothered to mention them!" Well, then he's using combined arms, and you apparently are not. Zone the 120mm out, it'll lose vs any other mortar in the game, so just duel it into submission. I've already mentioned the Dushka's narrow cone of fire. (oh by the way, you're getting your ass kicked by an off-meta commander if he has both of those, good job.) And actually try using your entire infantry force to attack him, but I don't mean blob and A-move in front of his MG. Overwhelm him with micro, he's on the defensive, it's only natural he'll have the advantage.