The downward spiral of comic book hero franchises

I have a simple theory about why comic book franchises tend to start strong, and then by film #3 it's more marketing and visuals than actual filmmaking.

Character bloat. It starts off as an interesting look at a hero and an arch-villain. Then, which each successive installation - more heroes and villains get added until it's a ridiculous ensemble.

Take the classic example of the Batman franchise.

#1 - Batman (1989). 71% on RT. Hero: Batman. Villain: The Joker (total: 2)
#2 - Batman Returns (1992). 77% on RT. Hero: Batman. Villain: The Penguin. Wild card: Catwoman (total: 3)
#3 - Batman Forever (1995). 44% on RT. Heroes: Batman and Robin. Villains: Riddler and Two-Face (total: 4)
#4 - Batman & Robin (1997) 12% on RT. Heroes: Batman, Robin, Batgirl. Villains: Mr. Freeze and Posion Ivy. (total:5)

-then the Nolan reboot-

#5 - Batman Begins (2005) 85% on RT. Heroes: Batman. Villain: Scarecrow. (total: 2)
#6 - The Dark Knight (2008) 94% on RT. Heroes: Batman. Villain: The Joker. Wild card: Two-face. (total: 3)

Let's take another example: Spider-Man.

#1 - Spider-Man (2002). 90% on RT. Hero: Spider-Man. Villain: Green Goblin (total: 2)
#2 - Spider-Man 2 (2004) 94% on RT. Hero: Spider-Man. Villain: Doc Ock. Wild card: Harry Osborn (total: 3 )
#3 - Spider-Man 3 (2007) 63% on RT. Hero: Spider-Man. Villains: Venom, Sandman. Wild card: Harry Osborn / New Goblin (total: 4)

Another example: Superman.

#1 - Superman: The Movie (1978). 93% on RT. Hero: Superman. Villain: Lex Luthor. (total: 2)
#2 - Superman II (1980). 87% on RT. Hero: Superman. Villains: The trio of Ursa, Non, Zod. (total: 2 - yes, I know there are three names but effectively they act as a single unit. They arrive together and leave together.)
#3 - Superman 3 (1983). 23% on RT. Hero: Superman. Villains: Superman(!), Ross Webster, Badass Computer Thing(?) Wild card: Gus (total: 4-5? This is a strange one due to the Superman duality and the computer-thing.)
#4 - Superman 4: The Quest For Peace (1987). 11% on RT. Hero: Superman. Villains: Lex Luthor, Nuclear Man. (total: 3). [But it must be said: This film was a piece of crap on so many levels it's hard to pin the problem on anything a subtle as the # of heroes and villains... ]


And recently, Iron Man:

#1 - Iron Man (2008). 93% on RT. Hero: Iron Man. Villain: Obadiah Stone (total: 2)
#2 - Iron Man 2 (2010) 75% on RT. Heroes: Iron Man, War Machine. Villain: Ivan Vanko (total: 3 - BUT, it's easily argued that Hammer as another Villain, or Black Widow as another hero. And then there is Nick Fury... )

So what might we take from this mini-analysis? Perhaps the sweet spot for comic book heroes is film # 2 - with a hero, a villain, and a wild card. More than that spreads the screen time to thin, and doesn't permit the title protagonist to develop a true relationship with a villain (that the audience can see is evil, and must be stopped). And it could be that a "wild card" character keeps things from being the usual white hat vs. black hat buildup & showdown.