Great write up man, it shows well how Mikey isn't just the class clown that people assume him to be, but a very legitimate fighter all his own. I like how he stuck to his guns and pressed the offensive, demonstrating his competency and his capabilities as a martial artist, while presenting himself as someone to truly take seriously. The real Mikey, is like how he was in the "Last Ronin", and in spite of his comedic facade, it is a shame that most people don't or can't see that about him. I see what you mean too, in that people are perhaps considering the 1987 cartoon depiction of Michelangelo a bit too much, when thinking of Mikey in general, and that is a shame, as there is more to appreciate about him as a character, but your recap does work well in depicted his approach to battle in a way that is effective and respectful of who Mikey is as a martial artist and character, and in regards to that, I say that you certainly have done a great job.
I think Donatello has a fairly good chance here actually. While Chun-Li is a very aggressive and quick fighter, Donnie's a very resourceful and skilled defensive fighter in his own right. I can see Donnie taking advantage of that and blocking much of her offensive movements with his staff and body, while utilizing his equipment at times to create openings, smoke bomb-roomba combo for example, combined with offensives made when Chun-Li is distracted might work well in providing the opening for some extra hits, ontop of the electric currents ability to do damage when Li gets too close. Utilizing these elements, in addition to his skills, Donnie will certainly put up a decent fight, and based on his experience, I can see him winning here.