IMO Ubisoft should alternate between Assassins Creed, Farcry and Watch Dogs. one game every three years. that way each game can have a long and healthy development cycle, and each game doesnt suffer from fatigue the same way AC has.
that way they also free up a shit ton of the AC teams that have been working on AC games to do something new. their Ghost Recon approach seems to be a step in the right direction (IMO, im no ghost recon fan) if they can do that with more old IP's with the teams that would be free'd up from AC development, that would be good.
Ubisoft seem to be trying very hard to try increase the numbers of big IP's they have this gen. if The Division, The new Ghost Recon and For Honor are successful, i think they would have a very strong list franchises under their belt. and they should start giving their IP's some breathing time before releases.