ITW is an amazing show, and when I was in a community theater production of it, I loved it to death.
However, if there are so many people who want to be in a production, it's too bad the director didn't realize that ahead of time and pick something else for a show. Otherwise, either a lot of people are excluded, or the split casting creates unnecessary drama and confusion. In the school production of BatB I was in we had to double-cast the Wardrobe because the girl who got the part originally had to be gone for one of the performances, and there was enough fighting on that subject (who gets to perform on opening night, who gets to do the first student body performance, etc. etc.). I can't even imagine the conflict if every part was like that, especially since ITW is more difficult musically and acting-wise than BatB. It's difficult enough to find one high schooler who can play the Baker's Wife well, let alone three of them or whatever. I don't mean to sound harsh, but based on my personal impressions of the show, it just doesn't seem like it would work.
When our community theater company chose ITW, they had just done West Side Story
the year before, so they wanted something with a smaller cast that would feel more intimate. Of course there weren't as many roles available in ITW, but...
"That is the state of the art, my dear... that is the state of the art!"