Having watched and played a lot of tennis I have come to the view that the greatest movement you can have in tennis, assuming a certain level of technique, is pure, raw, speed and manoeuvrability. If you can get to the ball quickly enough you can chase anything down, and that can compensate for less than perfect technique. Anticipation helps, certainly for short distances, and great positioning footwork also helps (Federer in his pomp had beautiful ballet like adjustments), but in the end pure raw speed* is the best if you can only have one thing.
Which is why I put Borg at number one in my lifetime. He was unbelievably fast, and could track anywhere - side to side, forward and back, without ever tiring. His technique wasn't always the best in every situation but.....he was always there. A lot of the others on the OP list also had/have raw speed, but I think Borg just shades all of them. Someone like Monfils for instance might be extremely fast when he gets going, but he is just too tall to manoeuvre quickly. Chang reacted quickly but over longer sprints I would still back Borg.
* by speed I mean speed over distances up to 40 metres with a 180 degree change of direction. That would be a race from baseline to net, and then back to the baseline, or from side to side at the baseline, or across the baseline then to the net, etc.