I’ll take Germany to make things interesting.
Regarding balance, at low and high experience level 1v1, the game is fairly balanced. For intermediate experience and team games, the Entente definitely have the advantage. The main reasons for this compared to higher level 1v1 game play is that the CP openings need to be fairly optimized to get early gains before all the defensive lines are created and the CPs need to coordinate more than the Entente as they are the aggressors which is harder in team games. There is probably enough team games here on the forum to show that with fairly equal experience level teams Entente probably win 2/3 to 3/4 of the time.
I believe we have tried a few games giving the CP a small bid in the past, @Witt and @Private-Panic probably remember, which I think did make it a bit more balanced for team games. The only thing you need to be careful of is giving Germany too many land units in a bid as they can potentially steam roll France or Russia as the balance there is pretty close early on. So I would generally support either a pretty small bid that any CP can use (most will probably go to Germany) or a slightly larger bid that only non-German CPs can use.
But I’m fine either way if folks want to just play it as is or try a bid out this game.