Welp, I've looked through the other thread, and the only roles mentioned seemed to involve religious leadership and.... warfare.  It still doesn't give me a lot to work with, but here goes. 
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This thread is discussing whether we should alter sentient beings to switch the roles God has given.
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The discussion isn't what are the roles of men and women, but should we alter the roles ordained by God.
I'm not attempting to derail the thread, but I think it'll be easier to explain my thoughts on the question if I provide a rundown of my world view. >_<
My perspective on Earth-default: Young men should prepare to support/protect themselves, and eventually their wives and children should it be God's plan for them to have a wife and children. (Support, in this context, meaning to provide the necessary resources that have to be obtained outside the home.) Young women should be prepared to support and protect themselves - while that would be their husband's primary responsibility if/when they marry, a gal shouldn't sit twiddling her thumbs while she waits for her intended mate, and there can be extenuating circumstances where a woman has to step up to the plate if her husband is either unable or unwilling to fulfill his responsibilities (taking into account, of course, situations where the inability is beyond the fella's control - such as death or disability). A marriage is an equal partnership - one partner supports the family unit by leaving the home and procuring the resources that can't be produced internally, while the other supports the family unit by performing the daily actions that have to be performed regularly for the home to function smoothly. 
In my own home, I'd have to say that the classical Western model where the husband provides the monetary income and the wife provides the domestic support is what works best. I was the primary income-generator for the first four years of our marriage, and I found it fairly stressful. I also like to think that I'll be better instinctually suited to be the primary caregiver for whatever children we may eventually have than my husband would be. 
But. (And here's where I'll get into trouble, no doubt.) Human beings aren't stamped out with cookie cutters, and while men in general and women in general have different strengths and weaknesses that can be observed among a good percentage of the groups as a whole, the individuals in the groups can have strengths and weaknesses that go against type. I don't hold that it's morally wrong or unbiblical for them to have those differences from the common denominator. Ideally, God provides us with a spouse whose strengths and weaknesses complement our own. While I agree that it's a good idea to encourage a particular setup as a rule of thumb, I'd hate to see the square pegs subject to disapproval and judgement from the Christian community just because they don't fit in the round holes.
My perspective in a fantasy world: There are multiple factors to take into consideration, honestly. Do your characters live in a fallen world? Did that world fall in the exact same way ours did, or were there different factors that would influence the dynamic between males and females? Are your humans transplants from Earth, or are they descended from another line. In your world did God set the very same rules as He's set here, or has He perhaps altered the "experiment" a bit, and provided a bit of additional dispensation based on His salvation plan for that world? Personally, in the worlds I've been working on, I've decided that there are a few things He'd be willing to tweak, though in my case it was so that He'd allow the use of magic (which is usually a neutral force that could be used for good or ill in those worlds - as opposed to here, where in my opinion you can either have God-sponsored miracles or situations where a demon might lend a hand to lead sinners further astray). 
Where other races are concerned, I don't see why our creative God would make them after the model of human beings, only with their stats buffed. He didn't copy us after the angels (who are, by many accounts, genderless - and who don't enter into marriage partnerships), and while both men and women are created in His image (which has both masculine and feminine aspects, according to scripture) He's obviously not male 
and female. Having created at least two distinct forms of beings, He could easily move on to create additional unique peoples with cultures that look like nothing we could ever even imagine, and they would still be 
good. 
If your primary aim in writing fantasy is to use it as a tool to instruct your readers in how things ought to function in 
this world, then you've already set your agenda and you know your own answer. If you're more interested exercising your imagination and exploring what a world might look like IF God chose to do something differently (as Jack did, writing his stories about what it MIGHT look like if God had chosen to populate a land with talking animals, and to appear among them as a Lion), then you can certainly branch out and have individuals interact in a different way than they do in the real world. 
Oh, and for what it's worth - Tolkien's Dwarves are something of an oddity. In Middle Earth there are two races that are the Children of Iluvatar (God) - elves, and men. The Dwarves were created by Aule, one of the Ainur (or greater angels), whose specialty happened to be craftsmanship.
Wikipedia wrote:
Desperate for pupils onto whom he could pass his knowledge and unwilling to wait for the emergence of the Children of Ilúvatar, Aulë created his own race of beings, the Dwarves. However, he did not have a clear idea of what the Children of Ilúvatar would be like, and because of the presence of the chaos caused by Melkor, Aulë made the Dwarves strong and unyielding, and not willing to endure the domination of others [...]. However Aulë did not have the power to give independent life to his creations. [...] Then Ilúvatar spoke to him, asking why he would seek to exceed his power and authority by attempting to make new life. Aulë repented, answering that the drive to create was kindled in him by Ilúvatar, and that he only wished for other beings to love and teach, with whom to share in the beauty of the world. [...] Ilúvatar accepted them as his adopted children, however as it was ordained that the Elves were to be the firstborn race, he set the Dwarves to sleep until after the Awakening of the Elves. He told Aulë that while both were his children, their creation was outside the scope of the Music of the Ainur, and often strife would arise between the Dwarven race and the Elven race as the events of the world unfolded. 
Aule's wife Yavanna created the Ents, but that's another story. (And another interesting study in the marital dynamics of fantasy races!)