So you don't always have to disband units if you don't want to pay their upkeep anymore. Some units can also be harvested for food - mostly heavies and mounts, nothing that can talk. You slaughter the unit on one turn, and on the next turn when the corpse depops, free rations pop for units in the same hex.
Also, "harvest" is one more weird magical formality, like our empty slaughterhouse (related?). Need a commander in the same hex as the food unit. You actually have to strike the unit with the intent to harvest, but there's no combat involved. It just croaks. This means I could walk up to a dwagon and kill it with one punch, theoretically. That is almost awesome enough to try.
Self-Sufficiency Hack (?)
I'll have to look at the math of this but it seems like one more piece of the puzzle toward having a side with zero (or positive) upkeep. If you managed your cities (and maybe had a Dittomancer), couldn't you pop more heavies than you need to feed all your units and have a bubble side like Jack was talking about? But that could actually support itself without fighting? It might still have to fend off attacks, though. Or maybe it could act like an agribusiness for the neighbors and buy them off with tributes of cheap food or heavies that cost less than the