Absolutely not.
With positional flexibility, in theory a team like the Twins could just rotate their starting 9 to put the best matchup to the plate each and every at bat.
Or the rule would say you have to re-enter to play the same position. And if a rule needs a bunch of asterisks, it's too complicated and should not be considered. Every new rule creates new problems.
Plus, I like baseball as a team sport with chance involved. Just no.