I do like this idea but I think every subclass nerf or buff is just digging a deeper hole. But I do think you are completely right about abilities countering each other, balancing seems like a very delicate ecosystem one small thing could trigger a huge chain reaction. I propose that each class is reverted to its original state, in most cases this is its strongest point. Then one subclass should be chosen as a benchmark point and note this should only be done after the proper data is collected, but here's what I predict would happen, bladedancer and sunbreaker would dominate, sunsingers, gunslingers, nightstalkers and storm callers would be in the middle of the pack, I think striker, voidwalker, and defender would lag behind. Also the strong versions of these subclasses didn't necessarily exist together eg. Y1 bladedancer and 2.0 sunbreaker so my predictions could be totally off but I would choose a subclass in the middle that's strong but not op such as gunslingers or sunsingers then the other subclasses could be nerfed and buffed to the level of the benchmark using your system of having no ability that can't be countered by another. But always make sure you never buff or nerf the benchmark subclass, if one subclass is out of line then take it down a notch to the benchmark level and buff it to the benchmark if it isn't feeling the love. Nerfing and buffing random stuff completely messes up the balance.