Same was the case in Dawn of War 2, where Space Marines were always the most played race no matter how the balance state currently was.
i miss fighting against a coordinated team of 3 orks. cant believe i sunk thousands of hours into all 3 expansions, i just hope relic dont stop making more of it, dont pass it on to creative assembly!
anyways, the is2 is a great tank, good armour and sometimes a 1 shot wonder(i always smile when it 1 shots a vet3 infantry squad), except german tanks are more focused on killing tanks. so putting them side by side, is2 might seem a little bad, but thats okay.
isu152 and elefants however are a point of concern. the elefant is virtually impregnable by soviet conventional tactics and creates a HUGE tank denial. the only few ways to bring it down are 50mins of ptrs fire, lucky IL2 bomb strikes or maybe the 203mm precision(which i rather not buy) strikes. i alway have no idea what to do when it pops out in a 2v2.
same with isu152. this is a wipe everything unit in a MASSIVE range, can crew shock vehicles and snipe infantry. bringing a gun comparable to the is2, except with the range of a ICBM.
these 2 units are god damn difficult to balance imo. i would rather if they lose their artillery range, given a little more speed and traverse and put them in assault gun ranges comparable to su85s, of course with a fuel reduction.