Yeah, it would make drafting better. However, if you want to have synergy and not bricked cards, you can play Casuals or Ranked?
I really like the Arena as it is now. It's part of the fun, that I don't have any idea what cards I will get and if those fit together or not. Sometimes I get lucky, sometimes not, but when I get lucky, it feels twice as awesome.
Re-rolling one card could possibly, maybe, perhaps, work, if you can't affect the card that replaces it. But then again, it kinda spoils the deck building idea. IMO.