For more episodic stories, what do you think about basically "as needed" cast instead of featuring every cast member every episode? Which is the current trend for ensemble series. For example in crime drama TV shows like Bones, CSI, NCIS, etc - every "main" cast member is featured every episode, even the team's boss is heavily involved in the main team's case without much to justify their involvement.
The problem I'm having is that I can't justify all the character's there in every adventure. Like a 16-17 year old cat burglar might feel out of place in a case taking place in some posh socialite party or out of place in a research library.
What I'm thinking is keep my main cast but rotate them around, depending on the story like I do with side characters. They still might be mentioned in passing but might not feature. It feels weird to bring the character along but banish them to the backseat until they are needed.