I tested some non-Diablo budget options to beat Rend yesterday and ended up with Cariel/Xyrella/Samuro start and Rokara/Millhouse/Tavish bench for a full budget Rares only lineup. This is for normal, not heroic, because the heroic adds have too much health.
Samuro can be immune to the instagib, just make sure he has the highest attack. Rokara comes off the bench to replace Cariel, giving Samuro more buffs. Millhouse comes off the bench if Xyrella dies while the boss is alive. Tavish comes after the boss is dead, Explosive Trap kills all the adds.
Here's a video of how I did it too: Budget normal Rend guide