Why Brooklyn do it: With the news breaking that Kyrie and KD both want out you get, probably the best star type player that you're likely to get offered in Bam Adebayo + a young talented shooter and a 1st round pick also (you could argue that including Herro is something Miami would need to do but I feel this is fair value given Brooklyn don't have alot of leverage and likely won't have many players as good and as young as Bam who is a young all star on the table)

Why Miami do this: adding KD to Jimmy potentially makes you the favorite to win the East, whilst losing Bam is unfortunate, this move potentially gets you over the top and you can find an approximation of Bams production in free agency or via trade