there is no place for crowder and smart/bradley, they are not good at playmaking, these guys dont have that much of a trade value, they are system guys, some team may give a low pick but thats about it. Tatum and Brown are the future, they are going to take those minutes.
The reason why they dont have massive trade value is because they are not stars...but dont mistake that for them not being coveted. If Boston could keep all 3 they would but they just cant after landing Hayward. The Jazz want Crowder as do a lot of other teams. He has one of the leagues best contracts. What other players out there give you 14ppg shooting 40% from 3 and can defend like him for $6 million per year.
Smart is a coveted player by some teams as well. He is a quality leader and defender. He isnt a good offensive player but most of that revolves around his shooting. His shot is holding him back, if he gets that, he will be better version of a guy like Patrick Beverly for instance.
Out of those 3 though of course Bradley is the one the Celts would prefer to keep, to me he is the best 3D guy in the league because of his ability to shoot the 3 from spot up or off the bounce.