We won 2006-07 playing 4-4-2/4-4-1-1. Also we didn't play 4-3-3 all the time, it was always the mix. We still played with 2 wingers and 2 strikers in 2007-08, with Ronaldo, Rooney, Tevez, Nani/Giggs playing many games.
We also played 4-4-1-1/4-4-2 in 2010-11 win, with Rooney playing alongside Berbatov and then alongside Hernandez. Nani and Valencia were wingers, Valencia was injured so Giggs/Park played as wingers. Scholes was also close to retirement, he didn't start regularly. It was Fletcher and Carrick who started most games, with Anderson and Scholes rotating.