In Summary My Comments/Suggestions are:

• You certainly know how to pose quite difficult questions - I'll do my best, but this is just my opinion.
• Nadal has a short back-swing and when he makes contact with the ball he has a very sharp upward motion - this gives the added topspin that Jimmy Connors didn't have.
• Jimmy Connors hit through the ball and on afterwards a little high, but nowhere near as high as Nadal.
• Jimmy Connors did have topspin on his ball but it wasn't the enormous amount that Nadal has.
• Jimmy Connors hit through the ball with locked wrists and on into the follow through, whereas Nadal is using his wrists when he comes up the back of the ball.
• Best of luck with what you are trying to do. I hope that I have helped you.