Would you unperk the M4 as well? The T-34/85 is superior in many respects. Its faster, its gun is more powerful (counting HVAP, its currently the most powerful in the game), and its turret traverses faster, all of which would make it superior to the M4 for combating the Tiger II with a flanking maneuver.
What about the panzer? It would need an ENY of 30 if we're giving out free M4's here. Turret is vastly weaker, its much more vulnerable to strafing, and it takes significanly less damage to kill one.
Oh, and as to your concern about the KwK 43 (88mm L'71) dominating the terrain, I think you are over estimating how much open space there is. Area wise, yes, there is probably more open ground than wooded, but the trees often block shots any further than about 1500yds in some maps, and even down to about 800 in others. While a Tiger II would be almost impossible to kill if it was at the dreaded V85 spawn, on the Tank Town map (the one with the big center island, and a string of GV bases protecting an airbase) it would be hideously vulnerable to ambushes.