Toadstool leathers are not mushrooms. No central 'mouth'. Fragging a mushroom in this manner will not work. Fragging a toadstool leather like a mushroom won't work. With the mushroom the frag will die, but the center will grow out again. With a toadstool leather, cuttign the crown around the stalk will cause the stalk to form a new crown. Cut it down the center and it will die (probably).
Besides, cutting the crown and then dicing that into pieces results in more frags.