Some of the players are "best of the rest" I agree, eg Ashley Young, Luke Young, Milner and on his day, Petrov. When fit, I'd actually say that Carew is probably the closest we have to a proper top four calibre player.
However, too many are decidedly mediocre, and are nowhere near "best of the rest" eg Sidwell, NRC, Knight and Heskey, and I'm afraid, some aren't even that good eg Cuellar, Davies, Harewood and Shorey
O'Neill also has the problem in that the other two top 4 calibre players we had, Barry and Laursen, weren't signed by him, and he lacks the ability to replace them with anybody even close to being as good.