Well, the Dutch will probably be able to suppress the Indonesian nationalist movements for about another decade or so without the Japanese mixing things up down there.
Also, perhaps the League of Nations won't lose more of its credibility if the war is averted. I know that Mussolini's invasion of Ethiopia was another blow to their reputation, but the Japanese invasion of Manchuria was really the last nail in the coffin.
Well by 1937, Japan had already occupied Manchuria and set up Manchukuo. So that really isn't going to make much of a difference in the League of Nations credibility.
So the Kwangtung Army is already in the picture, which means averting the Sino-Japanese War is gonna be hard. Basicly your POD is going to have to reign in one of the most independent(almost renegade) military commands in history.
The renegade actions of the 2-26 incident enraged Emperor Hirohito that he personally demanded they be crushed. So even a full year before the Sino-Japanese war you've given Japan a clear example of junior officers taking matters into their own hands to an extreme.
Even though their attempt to assassinate Prime Minister Okada failed, it did effectively end his career. They actually killed his brother by mistake. Possibly having the assassination be successful could enrage the next government to it's senses.
Koki Hirota certainly did have the background as a civillian government official to attempt this, though irl it proved that he placated the military as much as one of their own would.
Another alternative would be to have Admiral Okada learn of the coup before it's instigated and crush it. Though a navy man, he was hardly a hard-liner, and could possibly keep the Army in check.
Regardless, Asia is going to be an interesting place. Chiang would be willing to play ball with the Japanese against the communists I believe, though his nationalist standings might get in the way of such a union. China did reject that Japan-China-Mancukuo bloc against communism in 1935 after all.