Could anarcho capitalism coexist with state-funded military groups?

Ive been really keen on understanding how an anarchocapitalistic state could work in theory. One of my main conflicts with this theoretical state is the existence of military groups. Either all countries dissolve their militaries or all countries use tax money to keep them running. Otherwise your nation could be at an overwhelming risk of facing an invasion (assuming you have no military allies)

This seems to conflict with the existence of a “true” anarcho capitalistic state, isnt it?What do you think? Thanks in advance and sorry if the question is kind of dumb