I'm picturing it start to finish. They have to infiltrate the pool, then they have to locate Visser 3, then they need a way to kill him without getting close to him because he has his personal gaurd around-that means they need to get dracon beams or explosives, which requires breaking into the yeerk pool's armory-then they need to get back to the Visser, shoot him, get away from his POed cronies, escape the 1,000+ controllers who are in the yeerk pool, then make it out one of the yeerk pool entrances that are sure to be guarded because the yeerks know those are the only ways in and out.
They have to do all of this without knowing the layout of the yeerk pool, without setting off any alarms before they shoot the visser, and without ever having been in a real battle before.
All the rebels will die. The morphers will almost certainely die. If they do succeed, Visser 3 is dead. The yeerks aren't defeated, they just put the next person in charge, but then there's no one left to fight them, so the yeerks win.