The Butler thing actually does make sense. I realize it will not make sense for people that see no point to competing now, but it is easy to see a scenario where Ainge is asking on Butler, Chicago says the number 1, Ainge thinks that's too much, then says what if I could get you the number 3. So now it's #3 and whoever for Butler, and #1 for #3 plus future picks. So Danny gets the guy he wants in Butler, and gets something for winning the lotto in the extra picks.
Butler is attractive because he's better than Hayward (argue all you want, but it's true by almost any measure) and on a cheap contract for the next couple years. I think it is pretty easy for the Celtics to be under the cap going into next summer, and it is also possible for them to add some pieces during the season...or they could sign KO. With Hayward, you are pretty much locked in with no flexibility.
The downside even with the long game is that there is no chance a healthy Butler doesn't test FA after two years...and almost no way an injured Butler doesn't exercise his $20ish million option for that third year. And of course, the risk you are giving up a really great player in Fultz, of course.
To be fair, where I'm coming from is a place where if the C's had ended up #3 or 4 I wouldn't have minded at all seeing the pick go for Butler (even #2, presuming Fultz went #1)
This is not to say it is what I would do, just that I can easily see the "sense" in it.