Well for my 2 cent I have to offer up a different perspective. I've read the novelizations that said the Yoda/Dooku fight in AOTC was extremely one sided, with Yoda toying with him but on screen it was more even.
The novelization of the Sidious/Mace fight had Sidious playing Mace.
Now my point of view is a bit different. For over more than 20 years now I've been involved in martial arts and just because fighter A beat fighter B, fighter B beat fighter C doesn't mean that fighter A can beat fighter C. Plus Luke was correct about the emporers weakness being his overconfidence. I'm sure Sidious felt like he could dispose of Mace as easily as the other three, but the first rule of fighting is that you don't kick a kicker, punch a puncher or grapple a grappler. Mace's strength was the lightsaber, Sidious' was the force lightning. I think saber to saber Mace had the upper hand, force skill on force skill Sidious had it hands down.
Sidious was also extremely cunning and knew how to turn a bad situation to his advantage. When he couldn't physically beat Mace he played Anakin.