Robin was a kinda new character back then, she is serious but love to troll, dark humor, and she was still new to grandline new world etc. She had her past but she was still fresh to everything.
We have known Jimbe for a decade now so we already know his character, and he was already in 2 arcs with the SH (FI and WCI) and with Luffy for 4 arcs (Impel down and MF). So we can already judge a little.
Jimbe is not as quirky as the SH, not as fun, not as crazy. Jimbe jokes in the SH seem forced. I remember a time where he made popping eye face : this doesn't match him at all. Oda will change him to make him fit the SH and this won't work. Jimbe will lose both side.
The guy is also too experienced that he overshadowed Zoro and Sanji in their role and Luffy too. He overshadows their moments when they push Luffy, when they take over the crew etc. He stops a bit their growth.
Jimbe as the big senior advisor transform deeply the SH crew structure and for the worse for me. I don't need Jimbe each time saying the good thing to do, for either the crew not doing it or doing it.