Combative
Creative
Not too dissimilar
They're absolutely NOTHING alike. Diarra is an energetic, technically gifted, tactically disciplined defensive midfielder. He has a fantastic engine and tackling ability and is one of the best in the world at his role.
Barton is almost exclusively a right sided midfielder with good passing and crossing ability when allowed the time but not great at getting about the pitch and offers not a great deal defensively.
Honestly, they could barely be less alike.