0% is matched at the crosshair, so your muscle memory at the center of the screen will be consistent across the FOV range. But as your monitor match percentage increases, the crosshair becomes less and less consistent across the FOV range, and therefore, your accuracy at the crosshair will suffer.
Keep in mind that 75%, 100% and 56.25% are all arbitrary. They completely depend on the physical dimensions of your monitor. E.g. Take two monitors with exactly the same height and stretch one horizontally as if it had a different aspect ratio. If you were to match 100% on one of the monitors it would not translate to be the same percentage on the other monitor. See below.
The same principle applies to the vertical length of the monitor. Using the vertical does not make monitor matching independent. For games that crop/add the vertical length of the monitor according to your aspect ratio, you will once again have problems with arbitrary values like 75%, 100% and 56.25%. See below.
As Drimzi also mentioned above, the only percentage that is truly independent of aspect ratio, or more accurately, monitor dimensions is 0%. Once again, another reason to use 0% monitor match.