en_tn/num/01/20.md

the names of all the men twenty years old or older, able to go to war, were counted by

This can be stated in active form. Alternate translation: "they counted by name all the men twenty years old or older, able to go to war, by" (See: rc://en/ta/man/jit/figs-activepassive)

older, able to go to war, were

"older—men who were able to go to war—were"

counted by their skulls

"counted one by one" or "counted head by head" or "counted, each man"