Women should pray behind the men, there is a simple explanation for this, and that is because the shape of women's' bodies' can cause unrestrained feelings' of arousal's, of what is a natural reaction of a mans' subconscious response to the shape of the female.

Thus this is why this restriction was, I believe, ordained by Allah's law, imposed to keep the body clean throughout the prayer time ordained in our religious book of orders, the holy quran.

And other restrictions' of movement, in regards to this matter to, if people are more inclined in following the original text, then in some cases', women will follow behind, and not walk together, though these laws' are followed only by those that comply with the regulations' to please Allah, and or the law of the land .