Going to depend on form and injuries isn't it? I think Rooney and Van Persie could be a bit of an odd couple to start with. Both drop deep to get a lot of the ball but it sounds like Fergie means to use Van Persie further forward.
Tevez is an unknown quantity. You just have no idea whether he'll be on 20 goals or nursing some wound in Argentina at Christmastime.
Overall though I'd much rather be Mancini. City eased to that hairs-breadth victory last season with relentless, percentage-based football. They're strong from back to front and have a mob of cultured thugs in midfield who choke up matches. Felt United were fairly lucky to be where they were.