King Richard, both are very prone to collapse, so is France nowadays. Timurids usually do it earlier due to starting wars that make them fail to respond to a succession crysis properly which is more an AI fault than fault of their own country.
I played pretty much everyone on the map so far and from my experience as a merciless conqueror, I'd rank top5 like this:
* France - unlimited manpower, deadly NIs, crowd of slave-vassals since day one.
* Timurids - huge and unconquerable for AI. I often had Ottos lose 100-150k troops before they even got to Iraq. Imagine conquering all the way to India. If they didn't collapse, whole map would be painted red due to their easy cores they get from horde events.
* Ottomans - filthy rich, lots of manpower, great custom units. Can crowd west, can outgun east.
* Ming - unconquerable, rich and with huge manpower but also have crap units, crap tech group and crap religion (in the game I mean, compared with other religions, no offense to real life Confucian religion).
* Golden Horde - rich and populous horde starting with a massive army. They don't break apart easily and even if they do, states they release are quickly assimilated back. Menace of whoever it borders, even if it's natural born killers like Russia, Lithuania, Timmies or Ottos). Unconquerable until it starts falling behind in tech.