Do the women’s teams draw as many fans, and as many TV viewers, and generate as much revenue as the men’s teams?
That is the starting point, and I’d bet that current contracts are based on the past answers to the above questions.
The WNT actually brings in more money than the men in some years. However, most of the men play in the five biggest leagues in Europe where the pay is phenomenal. Unless it is a huge match between the U.S., it’s a “Thanks, but no thanks.” Their European clubs will not release them unless it’s for a major tournament which doesn’t interfere with their schedule.
Most of the leagues have a winter break of about one month because of weather, and most teams go to a place with nice weather to train, usually in Southern Europe.
There are international breaks throughout the league schedules for international or UEFA play.