I've been a-thinking.
I've hit upon something I like to call "pharming" (see what I did there? Good, isn't it?).
An army requires lots of crop production to get by. To supply them, you need to level up your crop fields. However, if you send your troops as reinforcements, they leech the crops off whoever they're sent to. So, if you send them to a low-population farming site as reinforcements, they will take their crops from that site as they need them (I'm not sure what happens if their requirements take the village into minus production and the village's stock goes below 0 - perhaps they die out?).
So, you don't need to supply your troops - someone else can do it. If anyone scouts the village as a farming site, they'll find a HUGE army.
Good plan?