Got a creative insight here, I can't feed the plebes with fish alone, the patrician area is swamped with food, but if I link their networks, everything goes to hell as the ladies go to get wheat instead of nearby fish and then nothing evolves. And you can't have a granary servicing two road networks as the walkers can use it like a road, so that's out. Then I remembered, if all granaries are full, food goes to warehouses, and then that I can transfer between networks
Well, so far so good, feeding people a bit more. Not sure if I have a path to victory here still.