Rogue DPS set

Am I being thick but with bleeds increasing our main combo point builder by up to 30% for SSL and backstab this basically favours SSL?

How is backstab meant to keep 3 bleeds up? Rupture and crimson tempest fine but the third would be what, garrote? An ability only useable in stealth, costs loads of energy and only lasts 18 seconds? Like how is this beneficial for backstab rogues?