>>27130572Megas don't break the game anymore than other powercreeps. In fact they make more mons viable in general.
No, a conventional Mawile or Sableye evo would not make them as strong as their megas did. It would also create problems like Eviolite Sableye. Plus, megas merely expand on their designs that fans already love, rather than turning them into some abomination like Rhyperior.
Just because some megas are poorly executed doesn't mean it's a bad concept.