I think it's a little more complex than that in a comic book movie. The number of viable villains is inversly proportionate to the amount of explanation or backstory each needs. So Die Hard is fine. You got Terrorist, Terrorist Terrorist etc. Bad guy with gun, insert funny accent and hairdo. Batman Begins is passable because once again most of the Villains stories can be quickly surmised from audience assumptions. Falcone is a throwaway mobster. Ken Watanabe is playing on audience "mentally fill in the blank" expectations. That leaves only The Scarecrow and Obi Wan needing a story. And even then it felt a bit crowded at times.Thunderous Cacophony said:I think Bob both hit and missed with his explanation. Movies with multiple villains work when they have an established hierarchy; Gruber and his henchmen, Bond villains, etc. Even Batman Begins had a secret organization, with each villain having his strings pulled by another.
Audiences can accept that two villains might team up, but not when they don't have a reason to do so. Movie antagonists tend to have one big motivation (take over the world, resurrect a loved one, etc), and when that obviously clashes with the other villain(s), we want to see the problem dealt with, either openly between the villains or through a big reveal.
Contrast this with the classic worst offenders. Spiderman 3, each Villain had so much going on, and so much that you needed to do that it got overwelming. The movie had to show how and why each villain got to that point, on top of the hero and his supporting cast. There's a reason that most of the bad guys (and a disturbingly large amount of good guys) are simply left as one note background thugs in the better XMen movies. In XMen one you have Primary Villain Magneto, gets full story. Head Henchman Mystique, gets a little bit of more fleshed out abilities but no real story. Sabertooth and Toad are completely flat. No story. No background. Just big shreddy guy and tongue guy.
The thinner you spread the villain story, the less effective the villains get in riveting the audience. Yeah you can and should have multiples. But as you say a hierarchy helps, and at the end of the day its a factor of how much you have to put into each one to elevate them above the threshold of disbelief.