Kabuto Sumo insert (one half) remix

My Kabuto Sumo midsize pieces were a little too tight and didn't fit in Skippacheco's model.  Everything else fit great.  I thinned some walls, made the mid size piece sections bigger and cut out the bottom of the wells to save filament use.  I also made the player token slots a tad larger to fit the wooden/carboard tokens in a little less snug.