Having an Axis China TL where Chiang's personality is still essentially the same will be an Axis China which is essentially millstone around Germany's neck.
Well I would leave room for possibilities here.
There was some cooling in support for Chaing in the mid Thirties before the Fighting with Japan started,
No with closer Ties and the need for Germany to have secret Weapons sight. Maybe China ( a very long way a way ) and a few more earlier German Trained Divisions Bagging more Communists ( ie like Mao ) you probably get a better performing China that might push Japan enough to realize it cannot fight China and The Western powers at the same time.
Having an Axis China TL where Chiang's personality is still essentially the same
Well probably not having the same personality. Wars have a way of effecting personalities, with the experiences in them
1.He fought for a Nation he came to respect and found it on the losing side
2.He saw and fought with an army so unlike the Corrupt beast he had at home, And would have a massive appreciation now of how important it is to get that sort of Discipline and Professionalism.
3.A man that has seen that Low Ranking initiative can make the difference again and again.
4.Also how important the Senior NCO's are to an Army and their need for education
This is a man who would come to despise the warlord system passionately and unlikely to be using it as a tool of getting to power by keeping the warlords divided, More likely would be looking for a way to crush them.
I am thinking these would be Massive changes and would lead to a very very Different China if he was to become leader this time round
I am thinking this would be a very Different Chiang