Prince Heathen and Famous Flower are two very different songs requiring requiring very different approaches.
I've heard C's Prince Heathen, and again - not enough vocal strength for my taste; Bert Lloyd (who virtually re-made the song), got away with it with the use of recitative. Not heard Cathy's F.F. so I wouldn't pass an opinion.
Happy to disagree; it's what these forums are about.
Jim Carroll