Actually, this is always one of the areas where the team has more debates. Fortunately for the human being, but unfortunately for the game, the AI still hasn't the capacity to beat the player through intelligence only.

We always have the usual drama of trying to balance historical accuracy (which is our main goal) with playability&fun (prevent the game from being a walk in the park for the player) and with AI expansion.

So, much effort was put into EB1 to balance those things and surely the team will put more effort into EB2 for the same purpose.

As a sidenote, making the rebels more powerful turns the game a little bit more difficult and slow for the player, but surely makes the game far more difficult to the AI (which relies on automatic calculations) and thus more easy for the player. So in other words: making the rebels stronger only makes the game indirectly easier for the player, and we don't want that, do we?