Have to disagree Dennis, I can point to many examples of Fly Police. Not only here, but at my local TU and local fly fishing shops.
I do have to agree that I am not one of them and often "go rogue" and tie patterns with no only substitutions but flies that I take different characteristics from other standard patterns and "Mix 'em up" to creaste something that has no name but catches fish.
Life's grand perch, do whatever you want.
Rick