Denver:
Offensively, I don't see much advantage with MPJ over Cam Johnson. But defensively, Cam has the edge and Nuggets would need that.
KCP opted out and signed to a Orlando. They need a replacement glue guy. Green has been good all-around player, very active. I believe in Denver developing his shot.
Powell with that contract, is good enough. He can still defend and good Pick&roll
Dallas:
Mavs lacked the firepower offensively vs Boston in the finals. MPJ being the 3rd scorer has been a proven in the finals.
Then re-signing DJJ on a min vet, making come off the bench will be great.
Brooklyn:
Ryan Dunn has been drafted at 28th Pick. That's a good wing for the Nets to develop in the future.\
then unprotected pick. addition to their 1rp stash