How would you handle "over saturation" of a character or how do you know it's even happening? I sort of wonder if that's even a real thing that's expressed in sales or if it's just a concept created by message boards. Also, with that in mind, I wonder if you had a line of comics that was, I don't know, 60% wolverine comics but they all sold a recording breaking amounts, would a company hold it despite the lack of variation? It's hard for me to tell where business stops and story quality begin.
I don’t think you can equate story quality with story quantity, though—one doesn’t have much to do with the other. Certainly, four excellent Wolverine books is better than two lousy ones.
This is one of those areas where my opinion has changed over time as I’ve experienced more and lived longer. If you’d asked me several years ago, I likely would have spoken about some tipping point where you have too much and everything crashed. Part of that is that I grew up in a world where there was one X-MEN book, one AVENGERS book and, well, three SPIDER-MAN books (counting MARVEL TEAM-UP.) But today, I think that, while there is a tipping point potentially somewhere out there on the horizon, it’s nowhere near as close as we sometimes like to think (or fear.) What matters is the quality of the work. How many BATMAN books are there at this point, every month? How many WOLVERINE books? And still, those characters are more likely to sell better than, I don’t know, THE FLASH or STORM. The audience likes what it likes, and so long as what you produce is good, they will always be content to have more. It’s when the quality goes down that you have a problem—but you have that problem with there being only one book as well.
If I had a line that was 60% record-breaking WOLVERINE books, I would likely continue to try to experiment with doing other things. But I’d probably additionally add more WOLVERINE books, in part to counter-balance the risk of producing FLASH or STORM or whatever.