Kitten also comes out for some basic hygiene stuff, as she's the one who likes taking baths and showers and making them look nice.

It's sort of catch-as-catch-can, honestly. Tom tends to come out more when they have to talk to authority figures, or when they need someone out who can think ahead and plan around corners. Jay comes out in fight-or-flight, yes, or when someone more brash might be helpful--he tends to get them away from things. Leigh comes out in physical altercations. Raven comes out in school/learning situations more because she loves books and loves learning--she's like Hermione in that. :p Things like that. They all have specific *reasons* they were created and are more likely to come out for those reasons, but they can also just come out just because. Or because no one else wants to. Hope that helps. :)