Some are motivated by the competition, others aren't. If your school is very competitive, it might help.
Either way, it is worth noting that mixed seating within a section can be a good thing. It doesn't really make sense that we so often put the best players of the section the furthest away from the worst players in the section - and they're the ones that could benefit the most from being next to the good players.
Not saying either way is better - just giving my thoughts on it.