No, don't shut up Mel

I think these are a very good observations. Just from memory, I'd say it even fits into the palindrome/inkblot theory.
The post bear-encounter scene is roughly as far from the beginning of the movie as the lake scene fight is from the end, time-wise. And therefore both are equally far from the middle of the movie = the middle of the inkblot.
I could just picture Jack say "We gotta do something about
this food situation our relationship situation". Of course he said it with other words, but that's not too far from Jack expressed.
Both times (part of) the dialog is about "all they got"
Ennis (post bear scene): "Beans 'bout all we got left."
Jack (lakeside argument): " All we got now is Brokeback Mountain."
(PS: the deer is an elk)