Well they should care for chemistry because it brings championship. This is the foremost goal of a team owner, to be the champion and they can't achieved it without his team blending together to meet the goal. But yeah, GSW doesn't have the ceiling anymore to bring in another caliber player without sacrificing the current roster.
Chemistry can be build along the way. If on the way, the chemistry didn't turned out to what is was supposed to be then definitely that's the time we can called that there's no chemistry on that newly added players on that team.
We can't say right now that there's no chemistry once a newly player just arrived at their team. Like I said, it will be build along the way so for me I will give about 10-15 season games as a test.
Definitely agree as if you remember guys when Lebron James switch team from Cavaliers to Heat, many speculators believed that there will be no chemistry since Dwayne Wade owned the Miami Heat as this guy is the main man. But after some lots of games, we can see that their combination is kinda good and as a whole, the Miami Heat are playing great that time.
But for 10-15 games that is already too much. Maybe for me I will give 5 to 8 games.
Of course team chemistry comes with them playing games together for many games. But what worries me, just in case a caliber player such as Paul George will somewhat backfire on them. Remember the Lakers, with Shaq, Kobe, Malone and Payton and other top players? They reached the Finals only to self-destruct at the end as a result they were upset by Pistons lead by Chancey Billups. Sometimes is it good the everyone knows his place in the team because adding a new name will cause a disturbance or a problem in the end.
Attitude of each player has a huge effect on chemistry. Chemistry won't exist if all of them were veterans, if all of them doesn't have anything to sacrifice for every game they play within their team as a whole. Shaq anf Kobe were at their best and adding Malone and Payton became worst. Malone and Payton were playing for the sake of the ring which is good but they don't have enough strength since they're old in the team that is why Pistons won the championship.