I doubt if you implement my scenario, you would only have one horse enter the Belmont. If that were true, the Affirmed would have raced by himself...and so would have Smarty Jones, et al... but guess what... horses that raced in the other two races showed up to race one more time.
But you are still missing my point. So, I will bow to your superior knowledge about what trainers and owners would do under my scenario.