Any trade seems highly unlikely. I understand that MIA is a first apron team and PHX is a second apron team. Butler makes $48.7M, Beal makes $50.2M so I don't think this deal can happen.
It is really hard to make any trade work unless the player makes exactly what Butler makes. My earlier idea of Butler to CLE for Garland and Okoro does work (at least per the Fanspo trade machine). But that is the only one I have found so far. Giannis, Lillard, and LeBron all make exactly the same as Butler.
I don't know that CLE makes that trade but it could improve their chances to win a title the next couple of years. MIA would get back two decent, useful players, which is better than they are going to get in any deal I can come up with. MIA has to rebuild but they would have a decent core to start with:
PG Garland
SG Herro
SF Okoro
Big Adebayo