the prophesied Messiah figure was supposed to be a military/political leader.

Meh not really. There were tons of different messianic versions floating around. We know this because we have the dead sea scrolls where a fully religious figure is described that way, plus the writing of Josphius who talks about wandering holy men making that claim. Their culture was complex as well as their history. They “knew” that they had prophets who were poor, outcasts, military leaders, political leaders, kings, Rabbis, crazed hermits, magicians. Ezekiel and King David have very little in common except both were viewed as the rightful rulers of their time by latter generations.

Also Paul describes him that way. In Romans and Galatians.