Providing medical care is a difficult job. Providing medical care in the middle of a battle field, while bullets are flying and bombs are exploding, is nothing short of heroic, and it's what Bridget does every day. If you need emergency care in the middle of a combat, only she can help you.
These outstanding fighters are equally feared and respected throughout the city. As they don't belong to any clan, they are free to ally themselves with whoever they choose. And having them on side is a huge advantage for any clan that manages to lure them into their ranks. But if two Leaders are in the same team, both their abilities will be negated.