So, a problem with discussions about topics like this is that usually there is this belief that certain things couldn't happen due magic features, with one example being some people asserting that Yuan China and Wing China would implode since they weren't ethnically Han dynasties. Let's try to jump this part.
The Yuan Dynasty lost most of the south after the red turban rebellions. Could they reconquer everything all the way to Hainan? They still have Mongolia all the way to Baikal and inner Mongolia. Maybe they could invade or vassalize Manchuria for more resources and manpower in preparation to move south. For this scenario the Ming can implode.
The Yuan Dynasty lost most of the south after the red turban rebellions. Could they reconquer everything all the way to Hainan? They still have Mongolia all the way to Baikal and inner Mongolia. Maybe they could invade or vassalize Manchuria for more resources and manpower in preparation to move south. For this scenario the Ming can implode.