Here's the question: how do we get Tamerlane to conquer an empire similar in size to that of the Mongol Empire? Is it possible at all? When would the POD need to be?
Well, Timur was born in (according to wiki) 1336. This was when the Yuan Empire was going through a relatively rough time which would last till it essentially collapsed in 1370. Perhaps the Yuan survive several more generations, to the time that while they prevent the Ming Dynasty from being established, they end up being unified, but weak enough that Timur manages to conquer the entire area in one blow? That's a massive stretch, because I don't think the Yuan would have lasted too much longer, not to mention the fact that by the time Timur plans to invade China (in OTL 1402), I'm thinking the Yuan would definitely have collapsed. Even if they didn't, it's still a bit of a stretch, to have Timur conquer an area as vast as China in a short while.