Concentrated fire can certainly cut the Germans down a size.
In State Farm against PijusMagnificus, the only remaining German AFV's were a Tiger and an SdKfz 222. The Germans lost 70 vehicles, most of which were Marders, StuGs and armoured cars. The Marders were mostly taken out by Katyusha and mortar fire (they have a weak defence value).
The StuGs by mines, Churchills, 76mm AT guns and T-34's (and one was knocked out by a 82mm mortar barrage, the freak hard attack result of the game).
My losses are roughly split between T-70's (7 or so) and Churchills and T-34's.
My high gun losses are mostly due to many (AT) artillery units being Fixed. That's becoming a minor pet peeve with the game. You can't move them until the Germans can kill them.
German gun losses came primarily from bombing Nebelwerfer stacks and interdiction.
The high German men losses are mostly from Katyusha fire hitting large stacks or units in T mode.