Inafune might want several teams working on this, though. Might be a BIG project Capcom have got going on, and they'd rather not tell.
Again though, to me this all seems pretty straight-forward. This is the same guy who's been basically doing everything and including up to pleading to fans of Vampire to hit up Capcom, so that he can get the opportunity to work on a game. For the last two years, no less. He got a chance to sell his idea to Inafune last week, and he "won out". In cases like this, the most straight forward answer is usually the best one.
Also, for the most part, we can say this about Capcom's production studios now-a-days: there's not much in the way of intersection. Ono's team (SF4) and Nitsuma's team (TvC,MvC3) are both fighting game development teams, but they haven't collaborated for any of their past projects and have no plans to do as such in the future. They actually preferred the notion of bringing in outsiders like Dimps (SF4) and Eighting (TvC), as opposed to any "internal" help from other Capcom teams.
That's why Capcom, and hell, a number of Japanese companies has these multiple "Production Studios" for this very reason. The different teams are allowed to govern themselves and work autonomously. And believe it or not, the notion of how there is "competition" amongst these various teams inside such companies is still alive and well, to a good extent. That's why you don't see "big scale collaboration efforts" comprising of several teams at once. If Ono and Niitsuma weren't forced to work together for the sake of MvC3 (which should be a fairly big deal for Capcom), then we're likely never to see them work together on a fighting game together. And maybe, that might be for the best, giving the two's decidedly different approaches on fighting games...