High CPS cause different Knockback Movement Calculation

If you have a high Click Per Second Rate. The Client seems to calculate the knockback in an other way, that gives the player with high CPS an enormous benefit.

Players players with a high CPS have very low Knockback movement on X- and Z-Axis the Knockback Movement on Y-Axis seems to be the same.

You can see it better if the Player that hits the player with high CPS has a Sword with Knockback enchanted.

Good to see at 20-30 CPS

P.S.: This problem exists since 1.8