My wife and I are so perfect for each other partly because we are so naturally different in so many ways. I really don't know if "Godhood" is the joining of an actual "male" being with an actual "female" being creating a complete "godly" being, but it certainly rings true to me that "Godhood" is the state of becoming "complete, whole, fully developed" as "perfect" is defined in Matthew 5:48. I personally think that means we only can become perfect by developing all good characteristics generally associated as "natural" to either man or woman. I know in my own marriage I have been able to learn how to "become" more complete, whole and fully developed because I interact regularly with someone who is very different than I.
Maybe gender is an essential characteristic specifically because it is "naturally" limited and requires growth and combination and adaptation - the very process we preach as the development of Godhood. Perhaps we need a spouse to reach Godhood specifically because it might be impossible for some (or all) to fully escape our natural characteristics and become complete, whole and fully developed on our own.