What a great thread! I'm so glad it's been resurrected. I love the idea's here! I posted this before, my own thought of "Broken in Two" means to me. This seems an appropriate idea to post here.
I know the term "Brokeback Mountain" is what's also known as a "Swayback Mountain", two peaks joined by a ridge which reminds one of a "swayback" horse. A horse whose spine sags between withers and rump. You can see it depicted on the movie poster under Heaths chin. I had always thought it symbolized Jack and Ennis, two peaks joined, but always to be separate. It occurred to me that what Annie P. might have meant by picking that term as the title is revealed in the last line of the short story: "There was some open space between what he knew and what he tried to believe, but nothing could be done about it, and if you can't fix it you've got to stand it". What Ennis knew, and what he tried to believe are the peaks, joined, but always to separated by that "open space".