I think that any team should be able to try to win every game they play with a squad of 22 players. This is enough to cover any injuries, two players for each position. Reality is only what you make it, so given the right 11 players, they would try to win every competition, and play 2 games a week. For example the side below would at their peak have done just that.
Friedel
G. Neville, Puyol, Terry, Pearce
Beckham, Ince, Lampard, Giggs
Messi Walters