Thats because Sov and OST arent artificially gimped by leaving massive gaping holes in non doctrinal roster: Rocket arty, Heavy Tanks, Elite Inf, Premium medium tank.
I've been saying it for years but balance team gives the same lame answer that: its asymetrical game!!
Yeah you know what else is asymetrical? The over 13% win rate disparity between the lowest winning axis faction and the highest winning allied faction.
13%. Balance team is 100% responsible for the state of team games right now and they have been very clear they do not care about them at all.
with the removal/heavy nerf of faction gimmicks (USF/OKW/Brits) I agree with you there isn't too much of a reason to have half factions exist anymore. Ideally, commanders should now "add onto" armies rather then fill holes. Ostheer feels really good to play because their commanders add spice to their main composition.
In OKW's case, they had a lot of tools because of their original "gimped" faction design.