They lacked belief because I don't think Wenger gave them any before the match. He would've probably taken a draw before the match by the looks of how they played, which is unusual for him. That was never going to help the team. They looked slow and sluggish because of those stifling tactics.
It was noticeable that later on in the game, when they were chasing and had to go for it, they began to gain the upper hand in the midfield battle and were actually creating some chances. Had they been like that for more of the game, then I don't think our midfield would have had such an easy time at dealing with them.
Their midfielders can take a lot of time on the ball though, but that doesn't actually improve Carrick at all, does it? It makes him look worse, if anything, because it means that his interceptions were easier to make as he had more times to read the passes.
Interesting actually. Taking too long on the ball can actually sometimes be a problem of Carrick's, as is shown when our midfield struggles to cope with high pressure teams.