Just jumping in here to note that with a critfocused phantsm build, a mesmer can keep up 20-24 bleeds on a target if it live long enough to get up 3 duelists (16-20ish seconds).
With phantasmal haste duelists begin their second attack just as the bleeds from the first start to drop off. For some strange reason duelists stack 7-8 bleeds at 56% critchance+fury (math says they shouldn’t, but they do)