The idea seems a bit crazy, since Curry and the Warriors looks like a marriage for eternity. But if you look at the bigger salaries in the NBA very few of them deem more likely to be traded. And the guys who do aren't that attractive like Beal, Gobert, LaVine, VanVleet, Simmons, Irving, Ayton, McCollum, Randle, Poole or Grant.
Other trading partners for Brown could be Cleveland (you'd try very hard to get Mitchell), Atlanta (stacking up quality role players for depth) or Brooklyn (Bridges + assets). Coming back to the original idea, it makes sense to also let go of Holiday, who honestly isn't living up fully to expectations. With Curry traded and Thompson let go, the Warriors probably also want to let go of Green and his antics. We'd be merging the best players of the Celtics and the Warriors. Pretty insane.
Thus: Brown + Holiday for Curry + Green?
Starters: Curry/White/Tatum/Green/Porzingis