Why do the Magic do this?
Inconsistency & injuries have plagued Magic guards, there is a lot of promise in the backcourt but the rise of Paolo Banchero & Franz Wagner implies this team can be top 6 in the East (which they haven't done in over a decade) much sooner than expected. The decline of Gary Harris creates a lack of veteran presence on the roster, which will give great opportunities for Brogdon & THJ to support the thriving young duo in a tough playoff series. Assuming a 3-6 or 4-5 matchup, the Magic have a real chance to win a playoff series & fuel a team culture change.
Why do the Mavericks do this?
With the Mavs impressive start, making a move like this is for one simple reason: win Luka a title. After an incredible offseason & unlikely faces like Derrick Jones Jr & Grant Williams stepping up from the perimeter, the time to address the immediate pressing issues (Efficient Paint% & Rebounding) appears to be now. Deandre Ayton is a player that could have a big glow up with a coaching staff & system that utilize his strengths, which one could argue wasn't the case in Phoenix or with Portland's flooded frontcourt. The potential of adding a wing down the line with the stopgap system role players is certainly available, but with reliable players like Jalen Hardy & Josh Green it wouldn't be as pressing.
Why do the Trail Blazers do this?
The Blazers have a lot of options regarding how to rebuild their roster, but the first step is acknowledging the somewhat painful truth: this is not a retool, but a full rebuild with Scoot Henderson as the first major piece. When rebuilding, having a lot of picks at your disposal is crucial since even the best scouts don't hit every time. The opportunity for more picks comes from the several young frontcourt players that have been added in recent trades; seeing what you have in those other players can only help you. Trading Ayton & Brogdon allows these opportunities to anticipate what building a young core looks like. The Blazers need to be ready by the time prime Scoot would become a top player.