As already mentioned by @roronoa_fan , the problem isn't "too many SH members", the problem is tons of side characters who hog the spotlight and Oda ends up not giving enough love to the crew.
I used to dislike Brook and wished he didn't join the crew, however, I really enjoyed how Oda handled Brook in WCI, he got the poneglyph copy, he trashed that Caramel photo, his interactions with BM, and it was fun. It made me realize that Brook himself isn't a problem, he can be quite enjoyable, but the problem is that we don't have enough spotlight for him, because Oda adds tons of retainers, two tiers of commanders, Oden-wannabe, supernovas and who knows who else so that actual SH crew does get enough time to shine. I mean, sometimes post-TS SH look like their own pre-TS shadows, where instead of character development you get the same gag/defining trait over and over again.
This is exactly the case where less is more. So while I have fun stanning for a new nakama here and there, I recognise that for the sake of the actual SH it's better not to add anyone else.
I used to dislike Brook and wished he didn't join the crew, however, I really enjoyed how Oda handled Brook in WCI, he got the poneglyph copy, he trashed that Caramel photo, his interactions with BM, and it was fun. It made me realize that Brook himself isn't a problem, he can be quite enjoyable, but the problem is that we don't have enough spotlight for him, because Oda adds tons of retainers, two tiers of commanders, Oden-wannabe, supernovas and who knows who else so that actual SH crew does get enough time to shine. I mean, sometimes post-TS SH look like their own pre-TS shadows, where instead of character development you get the same gag/defining trait over and over again.
This is exactly the case where less is more. So while I have fun stanning for a new nakama here and there, I recognise that for the sake of the actual SH it's better not to add anyone else.