Think of all the resources you don't have to spend..

The Tims and Mongols appear northeast or southeast, and have a random goal.

I had a similar experience in my second campaign, only that I thought i was well out of harms way.
Guess who got surprised. (And subsequently owned.)
So, disband your defensive armies, build up an offensive one, and be a carrion-empire-builder in the timurid's wake.
Deus Vult!