Think the big difference is the change of approach with the players.
I think they both tactically play the game quite similarly. However based on Eccles at Bedworth’s supporters club meeting, it seems Lampard is alot more personal with the lads and as such has got better individual form out of them (Dovin and Simms being a big two).
I think Adi was doing a lot more of that work previously (not a issue as the set up required more of Robins time for other matters like transfers for example) and when he went, they couldn’t fill that gap.