Although I'm on record as having said we gave up too much for Williams, here are the upsides of the trade, as I see it:
1. Proven player who can play anywhere on the D-line, especially in the interior, an area of need for us
2. Adds a player who can pressure the QB, another area of need since Nwosu is lost for the year
3. No financial commitment beyond this year if we decide not to re-sign him (I think this is better than the 49ers committing $84 million to Hargrave.)
4. Yes, draft picks are valuable resources, but the returns are always unknown.
So it's a lot to give up for a half season rental, but there were reasons to do this, and definitely makes us better for this year. Montez Sweat would have been a better replacement for Nwosu, but he's going to definitely get a monster deal next year that we wouldn't be able to afford. Also, Williams, with his ability to play inside and outside provides more of what we need.