The physical strength difference between men and women may explain the absence of female military leaders — an analogy to firefighter standards.

Ancient military leaders went onto the battlefield to fight — you don't want your leader to be one of your weaker fighters. Mike draws an analogy to California firefighter standards being lowered for women (not requiring them to carry a body up and down a ladder), which he sees as dangerous. The absence of female military leaders may be about physical capability, not about the rightness of male authority per se.