There is really not that much variation in these distances. The confusion has a lot more to do with anatomical illustrations being vague and inaccurate, thanks to a pervasive sociocultural discomfort with vulvar anatomy. Vaginas are consistently shown as gaping excessively. Generally the glans is shown as exposed though irl usually the distal clitoral hood must be retracted for the glans to be visible unless aroused. Illustrations also do a poor job representing the vulva in 3d as it is usually shown from one angle. The presence of a clitoral shaft is customarily ignored. The urethra is often shown more anteriorly than it ever is in real life. Sometimes parts of the vulva are even labeled incorrectly in Gynecology literature (cabernosa labeled as glans, vestibule labeled as labia minora).

Consider illustrations provided in The V Book compared to those in anatomy textbooks. The author does an excellent job describing the anatomy in a way any layperson can easily understand. I’m also 100% confident that no man I’ve ever taught will have trouble finding the clitoris on anyone, despite the fact that my anatomy is by no means normal in appearance (my labia minora were completely amputated during a labiaplasty). This anatomy is simple and easy to teach if people just get comfortable enough to illustrate it and describe it correctly.