I think it depends on the game. T/20 or 1 dayer then Gayle, but in a test I would say Symonds was the better batsman
Never saw Hammond so it is difficult to comment on him.
Also, in that list, I would say Symonds is most like Sobers De Villiers and Kallis - more of a batsman that can bowl where as the rest are more bowlers that can bat except for Watson who couldn’t bat or bowl