anyway, this is not surprising : to have a good acceleration, as much as you can, you need power (or "powerband", "mean power"...), so you better be able to reach RPM higher than just the "max power RPM". For instance, the stratos engine is supposed to give its max power at 7000
(but you can suppose it is a classic small lie quite common in rallying : remember the 2000's car having "300hp" but able to get sub 4s to the 0-100kmph with more than 1200kg, while in real they were having at least 300hp between 2000 and 7500 rpm), so the real peak power is probably higher with some more hp, and you have a gearbox doing some classic 1500RPM drop between gears when hitting +8000rpm, leaving the engine running around the peak power RPM to maximize the acceleration.
Having cars hitting the peak power at the redline is not so efficient regarding this (NB : this does not mean Ferrari road cars are not accelerating quickly
), this seems then normal for a rally car to have a redline higher by a consequent margin than the peak power.