I don't think I mix up anything to be honest.
This for example is the graph of a 74kW 1.6L engine (VW). Its rev limiter is about
1000 rpm above its max-power-rpm.
This is a 92kW 1.8L Volvo engine, which has its limiter about 500rpm above:
This is a 128kW 1.8L Audi engine... about 1100rpm above:
This is a 270kW Porsche.. about 500 above:
An 88kW Alfa Romeo.. about 800:
A 96kW Fiat.. about 500 again:
A 183kW Jaguar.. about 1500
I could go on with this for a while.
You are right that there are engines that have their rev limiter just above their power maximum, or even
below it. But I guess they only do that to achieve better lifetimes. From a performance point of view, you'd be faster if you could rev the engine up to the point, where the next gears rpm would give you as much/more power than the current gears rpm.
To give an example looking at the first graph:
If you rev at 6000rpm, and the next gear would rev at 4500 rpm at this speed, it's time to shift up. If you rev at 6000 rpm and the next gear would only rev at 3500 at this speed (that would be steep, but let's just assume), you'd better go all the way up to the limiter. Simply because you have more power at these very high revs than you'd have in the low-reving higher gear.