Explanation: Australia, back in the 1930s, organized a military expedition to cull the out-of-control emu population, with rifles and machine-guns. The emus won. And without any formal officer corps, even!
(the other leaders depicted are Julius Caesar, Genghis Khan, and Napoleon, all military leaders famed for their brilliance)
Well okay, but in defense of the Australian army, it could be mentioned that a total of 3 men was deployed against many thousands of Emus. Even if armed with machine guns, those were the 1930ies, and weaponry back then (before WW2) was not comparable to what machine do today...