Well you know your field conditions better than I do but if you are using a forward rotation tiller it will push the tractor through slick spots. I played with my gear tractor (820) with a Howard tiller one day last year, I put the tractor in neutral just to see what the tiller would do. It scooted that tractor across the field at a good clip.
A counter rotating tiller would be a different matter.
Mine goes counter clockwise so you have to put it in gear to use it. It just basically needs to be pulled across the field around 1.5mph - 1.8 mph which is one of the speeds that we use.