Originally Posted by Protoss
What if there was some sort of a gradual transition? Caro could get used to dealing with someone else, perhaps a hitting partner or some kind of technical consultant, allbeit not in the role of a coach. Piotr could take a day off here and there.
For example, Michael Joyce started off as Sharapova's hitting partner but eventually became her coach. I'm not suggesting him as a coach for Caro, just an example.
I think she's had enough with these experiments and now probably wants just a stable team, people whom she trusts, around her.
Looking at her career so far I think the old team has taken her really far and it is understandable that she goes back to what worked before.
IMO Caro is more of a conservative person, not someone who is going to take risks and make many changes in case success is not guaranteed.