I would trade Smart and Brown for Beal.
Beal has a playoff career average of 22.7 points per game.
He's a legit star player.
Kemba + Beal + Hayward = The best 1, 2, 3 in the NBA.
That's assuming Hayward returns to All-Star form.
Add Jayson Tatum to that mix and it would be similar to that of Curry, Klay, Draymond, and KD.
I know there are a lot of Jaylen Brown fans who don't want him traded, but Beal is a sure thing, Brown is not.