for me, I find that Ash and Dawn compliment one another really well, they learn off one another and use what they learn in their chosen fields, they make an awesome tag team covering weaknesses either one of them has with each other's strengths, they sort of know what the other is thinking, they know when to say something to one another and bring the other out of a low time.
for me PearlShipping is all about using one another's strengths to cover the other's weaknesses and these two do it better than any of the other pairings involving Ash