User blog comment:Master Sima Yi/Assassinews 14-07-'14 – Two new Assassin's Creed: Unity trailers/@comment-24760042-20140801200335/@comment-3046679-20140804231102

The way I see it, Ezio got a second game, because there was still unfinished bit of his story, the whole "versus the Borgia family" arc. And that was fine as a finisher. But then they had to unnecessarily shoehorn in him into Revelations, because of a plot device we haven't heard a whistle of before, namely Giovanni's letter that mentioned Al's library. They could have very well used a new protagonist or went back to Al to give him a second game there.

So no, we don't really need multiple games for one ancestor. As shitty as AC3 was, it was a self-contained story of Connor and Haytham, expanded further by Forsaken. Ed got his own story fleshed out from start to finish as well in Black Flag. If they can keep going with that for the next people, I'm happy.