Compared to Real, Barca, Bayern, and even City, there is a distinct lack of top class players in our squad, and compared to many other clubs (Arsenal, Dortmund, Atletico Madrid, PSG) our players don't seem to gel nearly as well as theirs. We have no more than 3 or 4 players that would stand a chance of getting into all those teams' starting 11s: De Gea, Rafael, RvP and Rooney (on his best, but in my opinion he's way too inconsistent, and way too often well below par, even if he's been relatively good so far this season, at least compared to the rest of the team. To be fair he has a shower of shite behind him in CM, but still I think he'd struggle to get into the team of many of the aforementioned clubs).
Too many aging stars and key players (Vidic, Rio, Evra, Carrick, Giggs) that aren't even close to the level they were in '08, and yet 4 of them have (up until now anyway) still been considered part of our best eleven. And none of their would-be replacements are in the same class as they were. Add to that that we've lost players like Scholes and Ronaldo in the meantime and the picture gets grimmer.
So far this season, my impression is that SAF left Moyes an aging, weary squad riddled with mediocrity that only he could've squeezed one last title out of IMO, reminiscent of '04-06. We haven't played really great football in years, and our defense and midfield aren't even close to being able to compete with the best in Europe at the moment - especially our midfield.
I think Moyes has a bigger challenge ahead of him than many thought before the season, and that a massive overhaul is needed (which is why it's doubly, triply, quadruply disappointing that we screwed up so badly during the summer). Get rid of Rio, Anderson, Giggs, Valencia, Evra (leaving anyway), Young, possibly Vidic (might be wise to keep him another year) and possibly Fellaini (depending on whether his performances improve or not, but I doubt it) at the end of the season. Buy 2 CMs (both of which should be top class), a RW, a LB and possibly a CB in January/next summer.