I never noticed until now...
...the choreographed fight scenes where Zorro fights multiple enemies are actually really really bad, but for one reason only; when Zorro is fighting he's moving rather quickly and deftly but if you pay attention to the men attacking him they're moving pitifully slow.
Obviously this is done because IRL it would be impossible for one many to fight successfully against two or more men at the same time. The way the scene is constructed draws your attention towards Zorro and how awesome his fighting is and completely distracts you from the fact that the men attacking him are moving really really slowly in order to allow the Zorro actor to appear to be holding his own in the fight. You'll notice multiple times where the bad buys had a completely open shot at Zorro but failed to take it because the actors needed to move slowly in order to let Zorro counter their attack.
When he's fighting another swordsman one-on-one however, the choreography is excellent and quite entertaining to watch.