I think it is going to be underestimated.
Play it turn 4 ->5 resources,
Play one on turn 5 -> 6 resources. Opponent -1 resource. Place a resource-> 7 resources, 2 spare resources
Play one on turn 6 -> 8 resources. Opponent now -2 on resources. Place a resource ->9 resources, 4 spare resources
Play last copy on turn 7 -> 10 resources. Opponent now -3 on resources. Place a resource ->11 resources, 6 spares resources
Turn 8 Illidan :P
Now off course you have extra resources left on turn 4,5, 6 and 7 to do anything else like say hibernate to increase resources for eg.
The only problem is that this means you need all 4 copies ...