I would be down for a Wallace for Williams and Shved deal. It even got the stamp of approval from the ESPN trade machine.
If all these three were on one-year deals, making it a talent for talent trade, I think Minnesota would take it. I don't think they've been impressed with Williams and it doesn't appear they'll pick up his option for next season, making him a free agent. Shved was very erratic last season and has continued to be so this preseason. If Wallace only had two years left they might take it but three years might understandly be too much for them. If Wallace resumes playing like he did before last season, which is a definite possibility, I think it's possible Minnesota could be interested during the season. They've basically already committed to their core so they're trying to win now. Wallace would help them more than Williams and Shved.
I'd be more interested in Shved than Williams because I liked what I saw when I watched his CSKA Moscow games but it's hard not to see him as a worse shooting Russian Jordan Crawford. Williams is a tweener who lacks the ability to drive and finish around the hoop or be highly proficient from deep. This deal would be more about clearing Wallace's salary. The Celtics still wouldn't have a ton of cap space but seeing how they scouted well with Vitor, I'd like to see who else they can get.