Tobar said:

I didn't see them complaining when the EU overwrote DROIDS which had A-Wings pre-ANH. The Rebellion is a large organization with many different cells. The main fleet is mostly composed of X-Wings. That there are different cells with access to different ships makes sense on a galactic scale. The Battle of Endor saw the gathering of many different cells into one massive fleet to take on the Second Death Star.

This can't be repeated enough. There's a reason it's called the Rebel ALLIANCE. Endor is the only time we see all the members of this alliance.