This would never, ever happen, but of course we would do it if we could. Its not even close. And that's recognizing that Fultz has little value other than expiring 12M after next year.
Generally, I believe everything the C's should do should be to compliment Tatum and Brown and improve our defense. Sabonis doesn't improve our defense, but Kemba is the team's weakest link defensively, so that's a wash here.
Sabonis is 24, he's cheaper than Kemba and he's a much more complimentary offensive player. Kemba just isn't a creator. He's just a scorer.