The key reason why Hideyoshi’s invasion was halted was due to Yi Sun. The only time he wasn’t in charge, the Samurai destroyed almost the entire Korean fleet in a single battle. That’s how critical he was. But these days you have scholars like Kenneth Swope ascribing a larger than life role for Ming. Fact was throughout that massive war right to the end, the Ming-Joseon alliance was inferior to Hideyoshi’s forces on land. Had Yi Sun not come back post Chilcheollyang disaster, its anyone’s guess how things would have gone.