I agree with sparrow. Not every single male or male body is stronger than every single female body anyway. Certainly on the average male bodies are physically stronger, but in certain aspects, like endurance, balance, flexibility, female bodies may be very competitive.
In addition, the argument about aggression and competitiveness is also a bunch of crap. In fact, much of our success as a species, as a nation, etc... is just as much if not more due to cooperation. Even the most successful of us, by any measure, relies upon others for many aspects. One might make a counter argument that women are better team players and therefore more important. In the end, neither is better or worse, simply having differences that compliment each other in a beautiful way.