Ok, please allow me to clarify a few things, as I went back and my post was harsher towards Jaylen than I had intended it to be. A few points:
1. I should not have used the term "worse," because this team is a complete juggernaut and I certainly do not think Jaylen is a bad player. The better term is probably "fit." I think there are a lot of players who make a lot less money and are less well-regarded as a player than Jaylen Brown who could plug in with the other 4 starters and there wouldn't be much drop off, if any. I believe Jaylen's skill-set, particularly on offense, is superfluous to the other four and his offensive approach brings an unnecessary risk when they are all on the court together. Thus, I think his best role is more of the traditional 6th Man, on the court with the less gifted offensively, and the task for Joe is finding which players best worth with Jaylen to maximize the value he can bring to the team. This doesn't mean Jaylen can't start, so maybe not your traditional 6th Man in that regards, but just in terms of the role he plays during the "bench minutes."
2. This is not a Jaylen Brown thing, but if Jaylen does sense himself and from media hype type stuff that he is playing a smaller role than he was before, I'm concerned how he, or anyone in his shoes, would take it. The guy just signed a massive Supermax deal, plenty of athletes in his position would not take it well. Regarding the passing issue I mentioned, there are times where Jaylen wants the ball and makes it obvious. He'll wave his arms around in the air or hold his arms out expecting the ball. Marcus Smart would feed Brown whenever he did that, but I have definitely seen a number of times this year where Jrue has just ignored it and run the offense as usual. It's a change. I'm not sitting here keeping stats or anything like that, but I do think the shifting role for Jaylen will bear watching and right now the on-court chemistry with Brown and Jrue is off, and the numbers, cited above, bear it out. As long as they keep winning, it's likely nothing will come, but if there's a losing streak or they come up anything short of a title, we'll see what happens.
3. Regarding 10 games is a "small sample size," I'd say both yes and no. Yes, in the obvious sense that these guys just started playing together and both players and coaches are figuring out the best fits to maximize results. Obviously there's so much talent a lot is just going to work regardless, but there's still work to be done in maximizing their potential. I also say "no" because we have seen a lot of Jaylen at this point, and he's never really shifted his game much and his talents and warts have been pretty consistent for a while. Particularly on offense, I feel like his game is a pretty known quantity. His main instinct with the ball in his hands just seems to be to take over and score, and overcoming so many years of muscle memory at this point is an uphill battle. And that might be a good thing...just not with certain other players on the floor.
4. Jaylen's defense, to me, looks maybe slightly improved, but I think it's more a function that he's now able to get away with being more aggressive because the help behind him is so much better. I don't really have any qualms about the defense, though, and the effort has been there. I do think he is clearly the least talented on that end of the four starters, but that's nothing to be particularly ashamed of with the insane level of talent surrounding him.
Anyway, just a few thoughts. I apologize for not explaining this better before, I had not realized how harsh the language came off towards Jaylen until I read it again. In my mind it was more of a how do we best utilize Jaylen thing. Admittedly, I also am in the camp who thinks Jaylen is the 4th-5th most valuable player on this team and almost certainly someone you want to use as a trade asset moving forward (where I definitely think he has value), but I don't think he's a trash player or anything and he certainly doesn't make the overall team worse.