Give me a self-propelled gun anyday of the week.
Marders are glorious little buggers when properly handled, because they're so cheap. All Gun, nothing else... Why buy a PzIV when you can buy 2 Marders? (Not quite, but close) Your dead just as easily when that 85mm T-34 AP shell rips through your hull... Just watch out for mortars, and dont bunch them too close lest they ignite each other... Converge on your target from many different angles at once with single or pairs of marders, instead of hunting in a single tank pack...
Marders to match Russian armor, towed infantry guns+organic infantry support assets to crush the Russian Infantry...
;-)