To compare him to other arms dealers seems to be a little like comparing Muhammad Ali to other, even elite, boxers. A movie was made about this guy, his connections must be without peer.
It can't automatically materially affect Putins war but it's a lot more, potentially, than he has now. I mean, how good can that stuff be coming out of N Korea and Iran, realistically? Maybe WWII quality, I'd guess.
So you answer the question: why would the US trade him for a basketball player?
I say he'll be of use to us or he'd have remained rotting in that jail. There are other prisoners we have who could have been offered up in a swap.
The anti-Biden people are maximally petty, true, but what's in this trade for the good ole USA?