Without the Shun Dynasty, I'd say a much bloodier end of the Ming--or even a "warlord era" that never truly ends. While Li was a great emperor, it must be noted that the one thing he is most famous for is his efforts at uniting the disparate warbands of the Shun army, many of them but common bandits hoping to get rich along Li's campaigns. Without the Shun, the dynasty's armies are sure to shatter into various warlords vying for control over China. Even if the Manchus were to unite China (highly unlikely if you ask me--the Manchu-Han ratio is even smaller than the Mongol-Han ratio in the Yuan), it would take far longer than the Shun's solidification of her hegemony.