Warner can bat, but he's not a great IMO, nor is he going to be one...
If you simply dichotomise into great or shit, then you must have much broader categories for both - and it can't be on average alone...
Not sure I'd consider Hayden a great, but he's got a much stronger case than Davey - S Waugh, G Chappell, R Ponting, A Gilchrist, N Harvey, A Border - all great, S Smith will almost certainly join that list, Hayden I am not sure of -
M Waugh, D Walters, M Taylor, M Slater, I Chappell, D Martyn, D Warner, M Clarke and many others - pretty f**king good, especially in specific conditions, but not great test bats IMO