I’d hardly call it unfair.
You’re tying up a lot of points in a single unit that generally isn’t very mobile. Defence 6 isn’t all that hard to disrupt, and once disrupted they go down fast. T-70s are one of my favourite units for this. Speed 5 (or 6 if you can zip along part of a road) can easily outflank a King Tiger or Tiger I. Their dice may not be spectacular, but they can get the job done. You may lose a couple in the process, but that hardly matters. Meanwhile you’ve at the very least kept his “uber” tank busy the rest of your units secure the objective away from whatever units he used his leftover points on.
Also, one shouldn’t put the Easy Eight anywhere near the same category as the rest of the heavy tanks. At best it’s a heavily armoured medium tank.
As for the IS2 you don’t even have to waste time trying to outflank it.