So many threads on this topic... The short answer is: nobody likely to move the needle. The really good centers mostly aren't available, and the marginal upgrades over Theis/Kanter cost too much.
On the Brown for Adams idea, the weird extension rules make it practically impossible to trade Jaylen Brown this year, and even if they didn't apply the salaries wouldn't match. You could match by sending Marcus Smart and a couple smaller salaries - Kanter and Romeo works in the trade machine. But I wouldn't do that deal and I have no idea whether OKC would want it.