The Corvette is faster because it has more HP in the lower RPM range, simple as that.
My point is not that the max. HP is a useful number and that max. torque isn't. The max. values alone are both useless.
My point is that to know how the car will accelerate I primarily want to have the HP over RPM diagram. Of course that could be calculated also if you had the torque over RPM curve. But if I have the HP over RPM curve why do I need to talk about torque, it doesn't add any information. And I will not shift where the torque is this or that but where the HP is this and that.
And for the M4 I will shift so that I will always stay between 5500 and 7500 RPM because power is a flat line there. If you end up below 5500 RPM when shifting you will lose time and if you shift past 7500 RPM you will also lose time.
This information can be directly seen from the blue power curve, while the grey torque curve contributes no additional information at all.
Sure if car A has more max. torque and car B has more max. HP then it is certain that car A will have more HP than car B somewhere in the RPM range, and that is why it *might* be faster. But you can only say for sure if you see the curve, and better the power curve than the torque curve, as there you can see it directly (all other things like weight equal).
Here is another example, this is the diagram for my CX-5 G192 with 192 HP and next to it the 175 HP Diesel (says Mazda 6, but they use the same engine in the CX-5):
So the Diesel has 17 HP or 12 kW less than my naturally aspirated gasoline fueled G192.
But it has 420nm max. torque while mine only has 256nm, so the Diesel has a more than 50% higher torque than my G192.
And guess which car will accelerate faster from 0 to 100 km/h? My 192HP G192, not the Diesel! (and not because the G192 engine is a bit lighter than the Diesel engine)
Sure I would have to rev my G192 like crazy close to 6000 RPM all the time and the Diesel will push forward much better at lower RPMs, because it has more *power* in that range. But still to get the max. out of the Diesel you look at the blue power curve and not at the pink torque curve, you would try to stay at ~4500 RPM where the max. HP is on the blue curve and not at ~2000 RPM where the max. of the violet torque curve is.
And if I would shift my G192 around the max. torque at 3250 RPM I would be completely screwed and probably take 20s from 0 to 100 km/h instead of 8.1s.