Enhanced Account Switcher | Accountlist only show x groups?

[doylecc]

Is this because they don't have accounts attached at all? Or just a weird quirk with Ash's account.

If Ash isn't also a member of an allowed additional group, then yes, it is because the other users of the same group don't have accounts attached at all.
Ash is shown because there is someone attached - even if the attached user is hidden. To change this behavior, the account list has to check the groups of the attached accounts before the list is created instead during the process like now - which would mean rewriting the account list.