Perhaps, but without doing root cause investigation we can't assume anything... and in Lean we wouldn't look on how to stretch a process to make it take 3x more, but how to make it happen without problems in the time already available or how to reduce time... so we could either separate the teams in 3 to give each 3 years in alternation or see how to improve comunication... Only increasing time would make the budget 3x higher with no economical gain, who would apply it?

That would only be true if the same teams that now make an AC game in 1 year were involved in making it in 3 years, which wouldn't happen. Even more, those teams that now are busy working on AC games could actually work on other franchises or even start new IPs that would help Ubisoft as they could have 3-4 strong IPs that could be launched one each year, giving them a steady income while also ensuring a certain quality in their products.

And yes, in an ideal world Ubisoft would find a way to solve all their problems and keep launching one AC game each year while maintainung the quality, but we don't live in such world. So their option is to either put more people or teams into the yearly development of the game and prey that the problems won't get bigger/worse, or pause the whole thing to evaluate which are the problems and where do they come from, then solve it and start to make game again. There is of course a third option, which is to give the project extra time in order to identify and solve the problems as they appear, trying to get rid of all the problems and, once done, increase the production rate again.

Now honestly, I think that the best thing that Ubi could do is give AC a rest. They have burned too many historical settings in a very short time that could have been used more extensively.

How reducing the team to 1/3 and extending the time by 3 times would solve the time constraints if they will have the same manpower in the end? Or you suggest to have everyone in the same location to streamline the control? Have you though that they hire other teams because of expertise not manpower for common tasks? This is why I said you can't give a solution without really knowing the problem. If it was as simple as just guessing they would have solved it already. And they won't give it a rest if it keep profiting.

Reducing the team and adding more time would could speed up the game development as some of the troubles described in the OP would get inmensly reduced, like the time used to make decisions and specially the communication one (it's a lot easier to discuss what's going on when it's only one or two studios, even more when they are in the same country and/or timezone).

And yes, of course they could ask the help of other studios for expertise, but when that happens game after game it's proof of how badly organized is the studio in charge. After so many AC games, Montreal should have the necessary talent to take care of most if not all the important aspects. C'mon, that studio also works on Far Cry, Splinter Cell, Rainbow Six and now WatchDogs. They are the studio the others should ask for help, not the other way around.

I've said reduce the amount of studios to obe or two, never only one. And yes, things could speed up because some of the decisions would be made earlier, wasting less time in the production of the game.

Besides, we have all worked with other people and have realized that, sometimes, sharing the same work with someone else (in this case would be two studios doing the same work) can make everything more difficult.

Also your Pininfarina example doesn't work. First because Pininfarina isn't part of Ferrari, unlike the other Ubisoft studios, but also because they don't work exclusively for Ferrari. In any case, Mahindra bought them last year, so I doubt we'll see more Ferraris designed by them .