I'm not sure I'm following you with the no leader thing. The leader should be clear on most team comps; they will certainly be first in the node description, and are usually placed in the center within the battle. Instakilling this person should allow the others to die.
The OP did not understand the purpose of the disk and as usual CG's description leaves an area to question. This phrase can be understood as you can kill the leader with an instant kill then others can die.
"Enemies can't have their health reduced below 1% while the enemy Leader is present, but can be instantly defeated".
In reality, you don't want to use the disk if you need to win the battle; you don't want to kill any enemy. Just use it to farm feats on mid and sector boss battles where you have 10 minutes to auto an enemy that cannot resist debuffs and won't go below 1% health unless you use one of the few toons that can instantly defeat.
Capital Games Team
