Not necessarily out of his depth but as I mentioned in another thread I think he has peaked.
His strengths and tactics suit the lower leagues perfectly but the Championship needs tactics with more guile and variation.
I still think he needs a decent coach working with him, not the "yes boss" Raynor type but a guy that's worked in this division before and knows the "tricks"
However I can't see SE welcoming such a man, as his ego wont allow it.