@nugger I don't know if you're aware of it or not, but if you're looking to flesh out logistics/economics, and aren't planning to do anything too absurd, then you may enjoy Adventurer Conqueror King System: Imperial Imprint (ACKS:II).
The guy who wrote it is a classical turbo autist (but in the DaVinci mold rather than the Chris-chan mold) and basically wrote a coherent late antiquity economic and logistical system to better simulate stuff for his wargame, then wrote an RPG around it. Starts from the price of grain and the productivity of the average peasant family and then built up to allow a world with coherent verisimilitude. It's complex, but not complicated, and it's descended from B/X DnD.
Plus, you get given the keys to build all sorts of classes/spells/magic/etc to build your world as you see fit, and it'll all be (more or less) in balance with the core stuff.
I think the RPG space needs more of that classic adventure fantasy that was prevalent at the dawn of the hobby. Reductionists, revisionists, racial inclusionists, and radical subverters have made what was once fantastical and escapist into gross sex grimdark, and it sucks. I like your ideas, and would like to subscribe to your zine.