True. I always prefer having one attack minded fullback and one more defense minded. Unless your team is using a diamond midfield, in which case you need both fullbacks to be good at attacking.
If both full backs are pretty speedy and decent at defending then it isn't a problem. In our case neither are all to good defensively, one is fast, and the other slow.
I don't believe they will win the league or even come close to it this season, but to suggest that the main reason for that is because they have Mancini as coach shows obvious bias against him.