The problem is there is a threshold of "ability", and the T23/76, M4/75, Panzer IV, M8, and M3/75mm are on one side and everything else is on the other with quite a gap between.
Tanks like the M4/76mm and the T34/85mm have a distinct advantage over those listed above, and are not far behind at all the "Big 3" (now the Big 4). So, where does HTC draw the line? It is easy to earn GV perk points, just like it is to earn bomber perk points.
I would hope HTC seriously evaluates their ENY values on the GV. I think the the ENY values need to change above all. Especially the M4/76, there is a reason the Sherman Firefly is almost non-existent any more. My opinion, of course.