If is the biggest part. If Chivu is good, then yeah Inter has a great chance to win the league this season, but that is only if Chivu is a good manager. So far we do not know if he is a good manager or not, it's a questionable thing and we have no clue about it at all.
We are just making an assumption, and because of that it would be very tough for us to accept that they are going to be that great. We are going to of course see how this could be that bad, Inter is a great team after all, so even if Chivu turns out to be not that great, it would not be an easy thing. But we can definitely end up with a lot better results when we are talking about it, it's going to be something that will be questionable for the long term.
A coach can certainly change everything even without extensive experience, but if he skilled at managing formations and strategies, I think chivu can transform Inter milan into a stronger team. I say this because I've seen xabi alonso successfully transform Leverkusen, and chivu could do the same. But we'll see how well he performs this season.
Furthermore, in Serie A, Several major team, like ac milan, are experiencing a decline in performance. This will certainly benefit Inter and other teams. But inter must work hard, as underestimating their opponents could cost them the title, as they did last season.