Do we really know if Yoda was or wasn't going all out?
Assuming Yoda and Sidious are almost dead equal (they're not, Sidious is superior) then it makes sense that Dooku outlasted Maul. That is why Dooku > Maul. Which is obvious anyway. Just like Vader > Dooku > Maul essentially. At least to me it is.
Dooku's calmness is only well-suited for exploiting mistakes that Maul makes, and that comes down to Dooku's precision more than anything else. Otherwise, I'm not seeing what benefits his calmness provides.
That being said, he's just better. Contrary to oft-made claims, Maul's strength could hardly press the Count and Tyranus is simply more skilled, powerful, knowledgeable, masterful, experienced, etc. Maul's more resilient, but that's about it.