Yeah, I didn't mean to imply that pools override miners' votes, just that they do set a default value in the batch files / scripts they provide, hence the 'dictate' in single quotes
Though hypothetically speaking, I'd imagine it would be possible to reject submissions that disagree with a pool's 'allowed range' of votes.  Of course that also means less rewards for the pool to begin with, and miners would quickly realize and change to a different pool so that's even worse for the pool.