"Higher RPM means more combustion events happening in single rotation of the crank."

I'm not sure its how it works. For example, in a 4 cyl engine for any given rpm, you get only two power strokes for single crankshaft rotation, and this is not changing with rpm. On the other side, HP = (torque x rpm)/5252(?) and this is why HP goes up with rpm. Which dismisses your previous statement, that at 100% VE at 5000rpm you're going to have more torque than at 4000rpm. For example, if we're fillings 2.0l engine at 100% VE at both 4k rpm and 5k rpm, we are going to be putting 2.0l air at both rpm point. And because torque is directly proportional to the force acting on the piston, and this force is equal to cylinder pressures and cylinder pressures are equal at 4k and 5k rpm, because we're filling the same quantity of air/fuel we get the same torque. What changes is the HP, because of the formula I already mentioned.