. . . but for low/no air situations would you go to your pony first or to your buddy?
I would train/practice to do one or the other, and stick with it. In other words, I would choose one of two philosophies: "I am carrying my redundant air supply that I can access when I need it" OR "my buddy is carrying my redundant air supply for me to access when I ask him for it." I don't carry a pony because I follow the latter philosophy. My training has ingrained in me a reaction to go to my buddy, who is carrying MY air. But there's nothing wrong with the other philosophy. If you prefer to carry a pony, then that is where you train yourself to go. Practice until it is second nature. The worst of all worlds is to find yourself needing air and hesitating and not being sure what to do.