During the space Battle of Endor, there should’ve been heavy casualties from both the Empire and Rebel fleet afterwards, not just a majority of the Rebel pilots surviving afterwards and most of the Empire fleet being destroyed.
For ex. during the Battle of Yavin, there were many casualties to Red Squadron where in the end only Luke, Wedge and a single Y-Wing pilot were the only ones who made it and not a majority of the Red Squadron pilots making it afterwards for a happier ending.
FIFM