I've been thinking about this myself

personally I would do it slightly differently

First of all I'm guessing you want all of them to be shadowstep it's an amazing talent ^^

so on that basis:

Start with1 Rogue = Stunlock - Cheap Shot opener! then Hemo and Kidneyshot as a finisher. cycle

2nd rogue Debuffer - Starts with Garrote (prevents a mage from blinking out of your cheap shot!) - SS as combo point builder - expose armour as first finisher - then switch to evi

3rd rogue - Main damage dealer - Starts with ambush - backstab as main combo point builder - and evi as finisher

I personally would be using the 3rd rogue as my main (you can position yourself better if you are constantly trying to be behind the mob/player)

or something along those lines specs were just off the top of my head and could be tweaked!