It was a struggle those. I call it a struggle because if he was so far above maul, and just decided to abuse the force he would have easily raggdolled maul.
You know just because something is not a struggle does not mean one character is completely on a whole nother level and out of the league of the other character, right? There was no 'struggle' but certainly Maul is not a joke to Windu. The fight lasted at most 12 seconds. You can't even call it struggling.
instead it was a fight which was cut short before it's conclusion, Mace also struggled with a droid as well.
I remember Anakin struggled with a Magnaguard, Eeth Koth with Commando Droids and some other situations. Everyone has low showings.
I think Mace is clearly above Maul...but he isn't far above him to where he can laugh at his attempts to kill him like TCW Sidious did, Mace would struggle to kill Maul.
Those are your thoughts. Yet to be proven. Mace may or may not have legitimately outdueled Palpatine and that can easily decide what happens with Maul. Frankly, because of Vaapad (Legends) and how it takes advantage of the opponent's rage and hatred, Maul would be in very deep trouble.