For instance Ostheer currently seem strong but probably because of certain commanders that allow them to take advantage of the change to the core units like earlier PG and stronger vet 3 grens.
Example for Wehrmacht: Pak 43-based commanders are useless because the game in general has too many ways to destroy stationary emplacements like it. They will never be an alternative to the Elefant doctrines for heavy anti-tank duty. It's not a commander problem, it's a COH2 problem. Making popular commanders less appealing won't fix this.
Example for Red Army: Partisans are a gimmick. Nerfing IS-2 commanders won't make them any more desirable.
Superheavies aren't anything that special anyway.
I agree that it would be much, much easier to change the superheavy+off map commanders than bring the others up to their level. I would suggest replacing the off maps with a more 1v1-type ability, and struggling commanders can have the off maps.
It is not easier or less disruptive to change doctrines that are currently the gold standard for playing the game vs. changing doctrines very few people even touch. Fixing what isn't broken...
Anyway, like I said, it's a fantasy that any of this will go through Relic. Your time is best spent making a mod if you don't like off maps in the game. They worked hard to craft all these airstrikes and artillery bombardments and they aren't going to remove them 7 years into the game's life.