if we had to use single point AF for the camera to focus properly to achieve a sharp image, then what's the point of putting 61 pt. AF when it will be useless other than a maketing strategy. As far as I understood, those points when selected will be the basis of the camera to focus on regardless of other settings. What's the point of having zones or expansion points if focus cannot be achieved? Does this mean we will need to use the 61 points individually?
Well, more points could help you to avoid "focus and recompose". The problem with the 5DII focus points, is there weren't many and they were all clustered around the center of the VF. And more focus points could help with bright situations when using AI Servo with moving targets. It just depends on what you are shooting, and what AF mode you need to be in. For weddings, I normally use "one shot" drive mode, and might only switch to "AI-Servo" when bride is walking down aisle and that sort of thing.
How does using assists help you not to do focus and recompose? It's actually FORCING that to happen at times.
If you are shooting fast lenses, wide open, close in, I'd think it might make more trouble, since it has a larger area over which to decided to toss the focus on and it might say make the eyes end up OOF I'd think.
It seems like a weird choice to use expansion points for the type of shooting you were doing, although I could be wrong no having been there.
That said, it sounds pretty worrisome, since that is what you would do for shooting sports at night and 2-3 seconds would make it ridiculously bad for shooting sports under poor lighting. I hope that is not the case.