The Rugged Terrain Tactic
It was something they'd learn later on by experience and trials, and that would help to accelerate their mission and widen the number of affected turtles by their combined attacks.
As things turned out to be this good, William controlled Charley to kill the turtles at their softest and weakest spots, their bellies.
He didn't want to speak about how to kill these turtles. Showing everyone the right way to do it was enough. As he expected, the moment Charley took down dozens of turtles, Stark sent more masters down there. And like this, a wide spree of killing happened.
Yet there was a single point that didn't match all these great things; the speed of doing all this and the magnitude of such actions.
The masters William's team gathered were in thousands, but they had to work together to either dig tunnels or flip these turtles. And so this limited greatly their speed of action, limited the scale of the entire process.