Disclaimer: This post is a random digression into things I find interesting but many others will not care about.
So, from the very beginning of the Expedition we knew that there were a lot of fairly important things being ignored as below the level of abstraction for this game. For example, every army in this era had huge numbers of camp followers, but while we had 10,000 dwarf and 5,000 halfling camp followers listed those were explicitly meant to represent civilian settlers planning to live in Karak Eight Peaks; we didn't count or even acknowledge the existence of the many thousands of human craftsmen, merchants, and whores that should have been dogging the Expedition's every step and generally being essential to its functionality, since it's unlikely that the mercenaries were looking to the halfling and dwarf followers for boot repairs, having their shirts sewn up, and matters of morale.
But let's talk for a minute about something also important: Food. In particular, let's focus on the fact that we had 750 large, carnivorous mounts accompanying the expedition. Given the weight of a horse, these mounts probably weigh around 500 kg each. How much do those eat? Well, the largest land predators in the real world are the polar bear (adult male weight 350-700 kg), and the tiger (adult male weight 200-300 kg for larger subspecies). Polar bears average about 2kg of food a day, but they're fairly sedentary as large predators go and outright hibernate to reduce food consumption. Tigers have more variance but it's usually about 5% of their body weight- it's estimated that a healthy tiger eats about one deer-sized animal per week. It seems to me that the tiger 5% figure is probably more accurate for giant wolves and demgryphs, particularly since we're pushing them hard as combat mounts.
So what does this mean for the expedition? It means that (750 mounts)*(500 kg weight)*(0.05 of weight in food consumed daily)=18750 kg/day of meat was consumed by the carnivorous mounts of our knightly orders. They primarily eat domesticated animals, of course- hunting to supplement that is important but unreliable, so a responsible knightly order leader isn't going to be willing to count on it to be able to support his forces' supply needs. Meat doesn't keep well so you want to feed large carnivores fresh kills, which means keeping live animals around. We can very roughly ballpark a sheep at 100 kg, a sheep at 250 kg, and a cow (large breed) at 1000kg; this is rough and not all their weight is actually edible but let's not worry about that. The expedition lasted three months and a bit, and the knightly orders will of course have ensured that they brought not only enough food for their supply needs, but also for the trip back.
So how many animals is in six months of knightly order food? The numbers above imply (18750 kg/day)/(100 kg/sheep)*(180 days)=33750 sheep, if the monstrous mounts all fed on sheep. If we assume a third of each domestic food animal, then 11250 sheep, 4500 pigs, and 1125 cows.
Thus, although the narrative never mentions it, we can conclude that our army was accompanied by nearly twenty thousand animals throughout every step of its journey, or at the very least, had a large fraction of that on hand and was consistently receiving further replenishment of such animals via the Barak Varr supply caravans. Needless to say, our invisible camp followers would have to contain enough herders to constantly manage all these animals. Presumably they heavily grazed in all areas that we passed through, and we were forced to feed them out of our supplies when passing through inhospitable areas like underground tunnels and Death Pass- let's not even get into how much feed twenty thousand animals would take, since we already assumed our ability to feed nearly a hundred thousand humanoids (2 kg/day, wagons carry about 800 kg, we're looking at sending home roughly fifty empty wagonloads of just food daily before accounting for animals or invisible camp followers). Many of these animals are probably still here, living in the East Valley and being cared for by halflings and some of our invisible herders who chose to settle. Panoramia is frantically trying to get grasses they can graze on to grow fast enough to replace everything they're eating because we certainly don't want to move our herds to unsecured areas.
It's no wonder that we say King Belegar is Stewardship primary because the logistics of this expedition were crazy difficult.