Why the Hawks do this: They get Bruce Brown, Anderson and 2 FRP swaps and 2 2nds for Dejounte Murray. Bruce Brown can fill in the void left by Murray and will fit better next to Trae. Anderson is a great role player to have on any playoff team and he'd likely extend at the end of the season.
Why the Timberwolves do this: They get Dejounte Murray.
Why the Raptors do this: They give up Brown for assets that fix their timeline. Fournier is on a team option which they can decline next season to create cap space for the IQ contract. They also get two young previous first round picks. 2 2nds and a FRP swap.
Why the Knicks do this - They are not going to give Fournier his team option next season. May as well get a good young role player and a 2nd round pick whilst giving them some cap space to operate any trades before the deadline.