Army Provisioning

Human to human transmission by a pneumonic plague is unlikely, how else can we account for the spread? What i was trying to think about was. How is there another mechanism of transmission that will be fair efficient but doesn't involve humans? And that's where i finally put a lot of pieces together and came up with army provisioning. This idea of army provisioning ties imperfectly with what we know from the historical record about the spread of the mongol empire. But once we get into the 12 fifties and up through 12 60, the mongols are moving through central urasia and getting us for assyria,. They bring their own provisioning from the foothills