Well. . .
Jangotat, being an ARC trooper, was pretty good. But he would have been positively tooled by either Kit or Obi-Wan as of Cestus Deception. So I don't even want to think about what Mace would do to him.
HK will be a royal pain if the others manage to keep Mace's attention and Force attacks away from him. if he manages to get some good shots in with the ripper, Mace may fall. If not, the Jedi Master's Force mastery will make quick work of him.
Canderous is the biggest threat here. Being a beast with his Repeater, he should be able to keep Mace occupied enough for the others to try and get a shot in.
But for this battle, I'm going with Mace. Having seen Depa deflect so many blaster bolts with such ease and precision leads me to think that Mace can handle these three for a little while. And with a couple of good jumps and evasive maneuvers, he should be able to get the ground he needs to chuck HK into a rock or something with the Force, then get the drop on Jangotat. Canderous'd be a pain to overcome, but with the other two out of the way, his fall would be inevitable.
If Mace can pick of HK, his victory is almost assured. Only Canderous would be a threat on his own; together, these three might be able to take out Mace. But my money's on the bad mutha******.