I also encountered some weird issues when I tried deleting only the crane gunner files. Perhaps the crane gunners use some files from the other nan gau warrior units. By deleting some more files I managed to get all female cranner gunners without weirdness and keep mixed iron hail gunners but nan gau crew also had to become all female to avoid weirdness.

Some weird issues came up when I tried

Why are craner gunners not mixed?