Take a look at this thread.

I had a same situation yesterday: opponent was 20% weaker, he took the lead. I could do, what I want, nothing worked (7:1 SoT to him). Opponent manger joined the game at ~40', I turned back the game with my STARTING tactics/formation, won 2:1, 12:10 SoT to him. That kind of bot-teams are really annoying.