Gorgonopsids (as discussed in Food and Hunting) may have hunted in packs. We don't necessarily know, because it's quite hard to find that out when you are looking at a bunch of sediment that is shaped like a skeleton. If they didn't hunt in packs, then they probably just mildly tolerated each other, like crocodiles today. They did see each other at water sources, as they were few and far between. The chances of seeing someone else at the one water source anyone knows of for miles is quite high. Smaller gorgonopsids likely felt intimidated and backed away from stronger, more dominant, beastly gorgonopsids. Also, it is entirely possible that larger gorgonopsids like Inostrancevia ate the dog sized Gorgonops.