[robogeek753]

If all six wheels are powered (which it sounds like they are) then they should function (kind of) like tracks. For the past six year our team has built tracks and we always put all drive CIMs at the rear of the robot, if for no other reason that there was room there. (we put the battery there too, same reason). It also makes them pretty accessible, because most teams put articulators in the center, not back.