I've listened to this song quite a few times, and I came to the conclusion that this might be Werra's best vocal. No sharing of vocals. If he had a first voice (treble) he could just be as good as JB but he usually sings in tenor which is not the greatest. When you compare the studio version to the live version
you can tell that studio effects enhance his voice. This song and Champion Kutula are his best vocals IMO
By the way, before Adolphe left, you would think he was the leader of WMMM and not Werra. Very dominant on stage while Werra was kinda quiet.