Buffy had her Scooby team. Every successful DC show has replicated this formula. It might not be obvious unless you watch the shows back to back to back though. After watching Smallville, Arrow, and The Flash, you can turn on Supergirl and wonder, "who is the character that is actually a wolf in sheep's clothing.
It really is a can't miss formula and only becomes obvious when you have three shows on one network using it at the same time under the banner of an expanded universe.