I doubt that DC dictates the Edition Size... Otherwise XM would of had to make 10k of it's Batman statue... I get why SS did it, who wants to buy a Lex Luthor statue if you can't get the Superman statue or a Killer Croc statue if you can't buy the Batman statue... it makes sense to take the 3 biggest DC characters and make lots of them to help the sales of other newer characters.
The side effect of that choice to make 10k statues of one character is the market becomes saturated thus the value of the statue goes down. Anyone who buys Batman, Superman or Wonder Woman for $450 will find if they decide to sell it a month later it will probably only go for around $300 or less.. If your a collector who never gets rid of his statues then no biggy... but those who like to change their collection every now and then it kind of stings....