Maybe I'm misunderstanding your point, but I personally thought that XY's cast and SM's cast were among the worst precisely because there were too many characters. I still maintain that XY could've done without Eureka, and SM could've done without Mao, Suiren, and Maamane.
Yeah, I was agreeing with you. Although, the more I think about it more, I think the XY gang barely passes the okay mark. Max wishes he was Bonnie. Serena's development was super late and rushed at the end.
Honestly, I think the XY gang would have been better if it was Ash, Clemont and Bonnie with a rotating 4th cast member like BW did.
Korrina, Serena, Shauna, Trevor, and Tierno could have joined at various points of the journey in XY with Serena promoted to main cast at the switch to XYZ.
In BW there were multiple arcs with a 4th companion, Bianca, Luke, Meowth, Stephan, and Dawn. So it would have been nice for them to reuse and refine that idea in XY.
As for Alola I would argue that Mallow and Sophocles were the only dead weight. Ash and Kiawe were the battlers, Lillie had her development, but I wouldn't want Lana out. A lot of the Ash and Lana episodes were really good and I love how passionate she got.
Something that early SM did well was having duo character episodes with Ash and a classmate. After a while, ALL the kids would appear as a group and no one would stand out. The character development would have worked out better if they allowed Ash to have minor appearances here and there so two classmates could have the spotlight. For example, a Lillie and Sophocles episode where they visit Molayne, or a Kiawe and Mallow episode where he takes her to a remote island for special ingredients.
The problem that Journeys has is that they finally have the dual protagonist deal...but the 2nd protagonist is written in a way that he's really polarizing that there's people that hate him or love him. Development is still so badly handled between the two mains that people cling onto the potential 3rd wheel because her development is much more interesting than what we are getting.