Lovely reading, Telkoth, and I agree with plenty of it...
Except for hunter-gatherers not having as much free time as farming cultures - the reverse is actually true, as hunter-gatherers actually spent less than half as much time obtaining food as farming cultures did. Hunter-gatherers actually spent most of their time on leisure, since they largely just relied upon simply using whatever was at hand to solve their problems rather than having to organize or work... it's just that they faced the problem that drought or famine would occasionally come and kill off all the young, weak, and elderly because not enough food would be on hand.
The reason that hunter-gatherers really lose to farmers, however, is that farmers are simply more populous than hunter-gatherers. It's thankless, back-breaking labor, but even wooden-plow-using farmers who could hardly harvest enough to feed their own families, much less export grain could cram orders of magnitude more people into a society than hunter-gatherers, who necessarily kept to groups of a few dozen when stationary, or a clan of a couple hundred when chasing some herd animal, and living nomadically. (The guy Telkoth links to basically says 180 farmers fit in 3 square miles, while no more than 2 hunter gatherers can fit in a square mile... that's a ratio of 30 to 1 in favor of farmers, even if only 3 of those 30 farmers can be in the standing army, or even anything but a farmer.) And that larger concentration meant standing armies. Hunter-gatherers could be a serious threat... but again, like the Mongols, that only happened when those hunter-gatherers were forced out of their lands by starvation, or they were forced to defend their lands for their own survival. Things like raising standing armies that could conquer neighboring lands just didn't happen without a serious food supply.
edit: As a total aside, the last bit actually made me think about something with regards to my previous statements about goblin chicken/pig ranching... farming something cold-blooded, especially insects, (although lizards or amphibians would also help,) would make for a far more efficient source of food per acre than chickens or pigs would, as they don't spend nearly as much energy just keeping themselves warm, and as such stretch the grazable land out to be able to support a greater population.
... Of course, a long-range "cattle herd" of insects might be an extremely odd thing to go herding. I'd imagine it be like "herding" a swarm of locusts across the land, and that's IF they can fly. (Flying increases caloric needs, but drastically significantly mobility, as well, especially for such small creatures.)
It might be possible to have some sort of mixed method of ranching, however - having long-range cattle drives over grazing land, and having the muck farms feeding an insect population for long-term food storage purposes. Plus, if those insects are purring maggots, they can be farmed for some lovely Dwarven Cheese!