I am aware of the problems regarding the willing cooperation/collaboration between Buddhists and an obviously militant organization - I had intended to elaborate more on the exact nature of their relationship in the IC, but the short of it is that theirs is a relationship of necessity rather than an actual willingness to openly associate with one another. Additionally, none of the monks themselves are combatants or soldiers - they merely have a rapport with the forces of the Jade Palace. They have been explicitly asked to help maintain peace and order in the region by advising and watching over the settlements; when it comes to actual peace-keeping and law-enforcement, the Palace usually steps in.
As for the meat: I never indicated that they partook, but it's not a great secret that there are entire breeds of domesticated goats raised solely for the meat, everywhere in the world - and not everyone in the Kunlun mountains is a monk. People need to eat, and it's the apocalypse. That said, there is a significant meat shortage (as indicated in the sheet), and I would be surprised if the monks were getting any of it.