[Wauthan]

Think of your assassins as bullets fired from a pistol. The target is chosen randomly. One by one the assassins have a go at this target until one of them manages to kill it. Then a new target is chosen and remaining assassins 'still in the clip' will attack this target. The process continues until all 'ammo' is spent.

Saber Cherry made a Battle Simulator. Check the links in one of the sticky threads.

The map you suggest sound very familiar. Not exactly as you describe but similar. It's on Illwinters map page.