Cerutty said that Elliott retired because his sex drive got the best of him. In later years Elliott himself said something to the effect that to continue and be successful he'd have needed to become, I can't recall the exact wording, but it was something along the lines of vicious or inhuman, and he didn't want to be that sort of person.
Clarke's comment was obviously meant to mean that Elliott's ability was more the reason for his success than Cerutty's coaching but Clarke was absolutely no fan of Cerutty so you can't take the comment as gospel. I don't doubt that Elliott may not have responded well to the daily track sessions of the era so you should give Cerutty credit there. Incidentally, Lydiard once told me how much he admired Elliott because Elliott always gave full credit to his coach for his, Elliott's, success which I took as a dig at Snell.
My point was that you can't evaluate a coaching method on the basis of one stellar performer because every now and again someone comes along who is just way better than everyone else. I really was thinking of the Coes and all the talk we used to hear about what great and revolutionary training Peter had put together as evidenced by his son's performances.
And no, I did not know that Elliott raced often after his retirement. Do you know anything more about the races?