I mean factor 2 is a bit much but if you want everyone to finish roughly in the same time frame distribution, you either have to do a shorter route or have the women start earlier. Otherwise you will have a decent time gap between male and female race finishers, which looks even worse if u ask me.
Gender equality is usually not about physical performance because everyone knows that there is a gap there that wont go away anytime soon. Its about socioeconomic factors like pay, medical issues, etc