Sorry to say, but a lot of times it's plot that makes it seem like 99% in favor of the jedi. In EU were Mandos are sometimes the protagonists we can see them kill many jedi but the plot armor for our heroes in the movies make them seem far weaker than they are. Plus, Jango had already killed AT LEAST 1-2 jedi in the movie alone including a JEDI COUNCIL MEMBER! (Coleman Trebor
) And we have no clue what he was doing in the battle up to the point Mace (who is toted as one of the greatest saber users of all time) dispatched him. So, honestly it's plots fault we don't see Mando bad***'s, the movies make it very clear (and they should be our basis for cannon anyway) that while jedi are powerful, they can still be defeated by non-force users.