I thoroughly enjoyed this background for two of my favorite bands. Imo, the Byrds were more informed by McGuinn, Hillman, and Clarke than by Crosby, but that may just be my prejudice. Info about Gene Clarke's stay in the Byrds is relatively scant (Crosby is probably the band's most prominent self-publicist). Do you have any details about Gene Clarke's participation in this encounter (from Rozzo or from your own research)? His songs (to my ear, e.g. "Feel a Whole Lot Better") are closer to Lennon-McCartney than are those of his bandmates.