I'd argue the best post Fergie side was still the side he left Moyes with. It got a lot of shit for being not good enough etc but I'd argue those players would batter pretty much any of our alternatively managed sides. That is to say de Gea, Rafael, Jonny Evans, Chris Smalling, Evra are better than our back four right now, and we still had Rooney, Kagawa and van Persie that season too. Maybe midfield has a stronger case for players getting in there - Fernandes and Herrera for me. And Rashford over Ashley Young.
Realise that would mean that I'd only have three players getting in to the post Ferguson 11, but that makes sense. His final 11 got 89 points. Our post Fergie best effort is 81.