I am not sure I understand your point of view. The sooner OP commanders that are used in the majority of game are nerfed the faster underlying balance issues will appear.
A classic example of this issue is the Dhsk performance. The unit was OP for years yet so little use because there more attractive commander. One might believe that he has brought a commander to the appropriate level but until the a commander has been tested thousand of time and every possible exploit has been tested one simply can not be sure.
The idea is simply nerf one OP commander can make several commanders meta. Buffing a single commander will have far less impact since it might actually see no use even if is brought to 100% power level.
Tbh I don't even think the DSHK was OP given its cost and timing. The issu was in the Soviet core, that at that time there was not a single unit that performed as Frontline infantry thus the DSHK was over used. I know you cite the close DPS but that's not a realistic metric given the function of an MG
The gun now is not worth picking a doctrine for as it's far to expensive to use with penals and cons are absolutely not an option (save for the new commander that allows cons to be, but even then you have really strong guards infantry)
Other commanders are not meta not because they are overshadowed, but because they are lacking. With the lone exception of spec ops because why the fuck would you not want uncountable recon and a no tech call in panther? But I have it on good authority that it won't be changed because despite all the tools at their desposal from elite infantry, to every flavor and price point of AT to defensive tech buildings okw wouldnt be competative without having a cheese commander and it's far easier to leave a crutch that ignores all the rules of the game than address the problems at hand.