I don't think Jodie could become the sort of Nancy they seem to want - I think they want a 'feisty teenager' as in the book, rather than a 'heaving bosoms, landlady'. Nancy is a YOUNG girl, who is like a SISTER to the boys. Jessie and Samantha I'm sure could be trained to say every word in exactly the way CM wants, even if it's not totally heartfelt. Jodie just isn't what they wanted - it would be right back to 'traditional oompahpah nancy', not breaking any new ground, which I think is what they wanted to do!
I can imagine they are having kittens about the boys - Gwion should be fine though, for opening night...the other two I'm not so sure!
The whole 8 shows a week is a bit unfair I think - no leading pro would do 8 shows a week, they would have a day off!