tedhebert
Emperor
I'm not 100% versed on how levied units work, but would this be theoretically possible?
1. Be Hungary's neighbor
2. Hoard envoys
3. Goad Hungary into declaring war on you
4. Wait for Hungary to levy a nearby CS's units and then upgrade them
5. Cash out your envoys into said city state, converting it to your side of the war
6. Levy now fully upgraded, top-of-the-line units and then march on Buda
Bonus points if you're playing as Gil and can now levy the fully-upgraded units at half cost.
Well... yes, but !!!
The levy cost goes according to the quality of units the CS has (and the number)... So in this case, HE would pay minimal to levy, then upgrades them freely, then you spend most or all of your stashed envoys, then you get to pay maximal price to levy yourself... I don't think you'd be able to do that very often and get a winning strategy