A “Mongol Divider” to keep the “Mongols” out? You mean to keep Kovio's Katten horde out?
Or did you mean to write “Finngol”?

Mongol-Finngol, tomato-potato. Finns, yes.

That's a big difference because kovio himself is the leader of the Mongols. (So if you were now waging an independence war against him building such a wall would make sense.)