John,
I don't know about the process and if Fazio walked away. I never heard that story, but it might be true. I know there was a grander scheme, of 18 holes but land was not made available and compromises were made.
You ask if Hanse could have done a better job under the same circumstances. I say yes, very easily; even with the same routing. The parallel holes would have been done in more of a differentiated way and you wouldn't feel that you were playing nearly identical holes.
Heck, I think I could have done a better job than Fazio in coming up with concepts and this was 15 years ago. If any of us armchair architects worked with a talented shaper I think it would have been much better. I know that is a bold statement but I think it is true. The routing may be improved upon, I'd have to think about that some more and walk the ground with a more studied approach, but the intra-hole designs could have been done far better within the existing routing.
Re-reading this, it sure comes across as boastful, but I challenge anyone to look at that work and not see a number of ways to improve it. I like three of the holes, but that's a small percentage that he got marginally right.