Ah, you've got me there. Evidently he was somehow able to overcome the Avengers once he merged his cybernetic body with that of the biological host.
I do wonder just what happened between his creation and his merging though; the twins factored a lot into that, and so I wonder whether there's an untold element here that could come into play somehow? Granted Wanda (assuming she even exists in this multiverse) would have only just become acquainted with her powers, but she should've been able to hold her own.
I'm thinking, quite simply, that the twins don't exist in this multiverse. Either Strykers experiments killed them, they were never born, or that Stark rocket went off on Sokovia when they were younger.