go for it!! if nothing else it will be a hell of a lot of fun, and you will end up with 4 of the highest dps class in game for pve ^^

can i give a few things i think might help for this team setup?

play it sneaky sneaky.

stealth: CS, Rupture and 2xambush any casters for a quick kill. (stun and silence + insane damage all in one) then immediately vanish as you said but use ur shadow step as a means of escaping the area ur in as the others will undoubtedbly be aware where you just were.

so quick kill, vanish and jump behind an incoming player with all 5 and run in the opposite direction. wait till your CDs are ready and do it again although the restrictions on those whirlwinds might mess this up