This article by zonal marking suggests a change in formation strategy by Sir Alex. He deployed 4-2-1-3 against Everton (in possession) and 4-2-3-1 (chasing)..
This suggests similar strategy as suggested by Gene in his old article about formation template for European games..
This was actually quite obvious from the acquisition of Van Persie and Kagawa..but the article of zonal marking discusses the problems in squad which will create hindrance in deploying this tactic effectively
Namely 1. Rooney's form .. 2. Lack of physicality & creativity in midfield..