I'm not sure I agree.
A faction being a little harder to grasp, but having the same power-level as other factions isnt what I'd called "imbalanced". Axis and Allies apparently have a similar winrate assuming both sides understand how to play, this is fine and good.
There's simply no sense in trying to balance around players who do not understand the game/their faction.
Nope you're wrong, if faction knowledge was enough then we would have 50% balance regardless of learning curve of each faction. But that's not the case, what bring this supposedly 50% between arranged teams (I didn't see any data supporting this claim) is communication that cover the gaps and lacks, with communication you'll obviously not ask an USF player lacking arty in its loadout to cover this function, but also - and more important
- you'll define the strategy before the game start with specific commanders on each player's loadout, thing impossible to do in random.
You can be the best player in random, if you don't have the correct synergy with your random mates on each loadout as allied, then you've already lost unless facing much weaker opponents. Axis do not face this issue as their stock army already cover 100% of the functionalities required in any matches.
Then there are other aspects that favor Axis such as starting with the best unit available or being able to build them right from the start and having excellent synergy. Maps that are at best balanced between factions but for a big part favor Axis and obviously the best end game units stock wise and only sharing this state with some Commander specific units available on Allied side.
HMGs and Spio can be defeated easily with communication early on, the same with late game big units even if you don't have yourself any equivalent on the field, with communication. But communication isn't an active part of the game design, units haven't been designed with communication in mind. Communication just appears to be a decisive factor today, but that hasn't been always the case when the game was so badly balanced, even communication couldn't help.
Communication allows players to overcome gaps and lacks but is not part of the balance. Remove those gaps and lacks and Allied factions will not suddenly out pass Axis one on the the arranged team win rate, it will probably promote and enable more strategies, diversity and more commanders.
But we all know that gaps and lacks aren't going to be fulfilled because Relic doesn't want. That shouldn't be a problem, you can still balance the game with gaps and lacks but not with the decisions taken on the last patches.