I know that it's the internet, but let's take a step back and look at this rationally.
First, we'll work under the assumption that Sheridan is correct. The Celtics have a bunch of of disgruntled players. Is it because of permanent issues, like management sucks and the players hate Stevens? I think not.
Here are the two issues:
1) There's a lot of talent on the team, and players who might be starting elsewhere are relegated to a bench role.
2) Kyrie is frustrated that everything's falling on him and that there are no grown-ups on the team. In other words, he's frustrated about #1.
So the Celtics trade for Davis. You have to assume that at least two of Rozier, Smart, Brown and Tatum are going out the door. Now let's look at the team:
1) We've just taken two players out of the 1-3 positions. Let's say that it's Smart and Tatum who go. Start Brown at the 2 and play the "3-man rotation" backcourt, like we did when it was IT, AB and Smart. It's not perfect, and Terry's not going to be thrilled, but he'll certainly see more playing time.
2) Kyrie now has his buddy AD. Instead of dealing with kids, we've now got Horford starting at the 4 and Hayward at the 3. I know that it's fashionable to say that Hayward is never going to be the same player, but I'm guessing that he'll look a lot better than he did this year. Brown is happy because he's starting, while Rozier will at least get a little more playing time.
3) AD spends 43 games a year staring up at the banners, wondering when his time will come.
But maybe that's just me.
Mike