Not the craziest of trades, but here's each teams rationale

Hornets:

Hornets have been a decent team in a weaker Eastern conference this year. Where this team really needs help though is on the interior. Poeltl has been pretty solid on a bad Raptors team and his age doesn't fit with the Raptor's current core. He would be a great fit for the Hornets as he could elevate there offensive game without them losing a step on defence. Bruce Brown too has proven to be a solid rotation player and although injured right now could bring some further vet leadership to this group. Additionally, the Hornets aren't giving up any of their own future picks so no loss there, plus at this point some playoff experience would likely be better for this group anyways.

Raptors:

Kind of a no brainer for this team as adding the additional picks would further help their rebuild. The players they add can slot into the rotation but don't really improve this team at all but I guess that's a good thing as they continue tanking. Also, I have noted it here but Josh Richardson along with Garrett Temple would be cut to make this deal work with roster spacing.

Heat:

The Heat do this trade to shake things up a bit and perhaps get some more reliable rotation pieces. This improve them much, but some fresh pieces on this roster who have been able to play winning basketball in the past is nice. Plus the incoming guys improve this team's defence which is where this roster needs help currently.