Okay, quantum leap time... I think HAD Justin done a stint in the Animals that he would have gone his own solo way by the early 1970s (his own uniquely creative genie would not have been content to stay in the bottle, so to speak). He perhaps would have gained some note as a lone artist (such as a Leo Sayers; Al Stewart; or Dan Fogelberg), but it's difficult to say what the songs would have sounded like without the influence of Mike Pinder and Ray Thomas, especially. It's six of one and half-a-dozen of the other as to how much who influenced whom, but songs like Nights In White Satin would not have sounded the same. I'm sure it would have been lovely, but it would not have reached the haunting quality it did without the Moody Blues involved in it. Justin was indeed a catalyst for the turn the Mark II MB's sound took, but Mike, Ray, John and Graeme were a catalyst for his abilities flowering, as well.

Difficult to second guess such things, isn't it? But I definitely think there would have been an eventual clash of musical egos between Burdon and Hayward. Justin's a gentle soul, but not where his songs are concerned, nor the performance of his music.

"...Songs to aging children come... Aging children, I am one..."
~~Joni Mitchell