Actually, the focusing speed is the #1 factor in sport photograp
many body could achieve above 10 FPS burst rate. My $600 D3s could do 11 FPS.
On the other hand, some of those zoom lenses focus so slow - 80% of the shots will be off focus with a fast moving target.
For example, I could get much higher rate of good shots with my 200mm F2 VR on D3s than if I had the 85mm F1.4. Some lens are designed for general purpose and their focusing speed is just too slow.
Again, I strongly believe the lens is more critical here.