Yes 6WD can push harder than Mecanums. So? I did not catch Dean saying this year's main goal was to push around other robots. In fact I see there is a rule against pinning and contact during certain match times.
Next year, when the goal is simply to push each other I will be on my way to northern Minnesota for these:
http://www.mattracks.com/
Good luck to all, have a safe build season!