Their strategy is too one dimensional is all i.e. to get Fu in the back and Cai in front.
I agree with this. They're almost unstoppable whenever they employ this strategy, but that seems to be the only reliable weapon they have. It's also too easy to read and counter, just as TG & CW or MK & HS had done.
Fu & Cai are the World Champs and the No. 1 ranked pair today. Based on these two facts, it may appear that they are the most dominant MD pair today. However, their lop sided losses in the JO & CO suggests otherwise.
When we talk about dominance, LD comes to mind because objectively speaking, it is difficult to question that he is the best MS player today. His dominance of his opponents like PG, LCW or TH, is not only because of his skill, power or quickness, but also because of his ability to employ different strategies. He can even change his strategy midway through a game just as we witnessed in the JO finals vs TH.