Thing is, no one flanks IS2. You get TDs versus it.
Well unless you're into puma heavy strat, PzIVs not worth it to flank. And flanking with patnher means you're endangering your 190 fuel tank. With good panther frontal armor, you're better off slugging it out with IS2, with some PaK support if you feel RNG is not on your side.
Yeah usually Axis got enough TD to slug it out, I used to flank IS-2 when I spam Puma when Soviet spam T3 unit, Puma with TWP turret lock IS-2 it is really helpless (Although at that time it is more the Soviet get greedy and he dive his IS-2 to chase my Command P4).
All valid point, usually Axis armor does not need to flank, too much risk involves but sometimes you got a window to exploit like his IS-2 walks into your vetted Pak/Stug or he hit a Teller mines.