Exactly. Part of the reason that Apple's chips do so well against Intel at a given power level is that there Apple is operating at the frequencies their chips

Exactly. Part of the reason that Apple's chips do so well against Intel at a given power level is that there Apple is operating at the frequencies their chips are designed for whereas Intel is far away from their sweet spot. You can cover a variety of power targets with one microarchitecture but you're going to do so less efficiently when you're far away form your design point. And while I bet you could overclock an Apple core somewhat if you used liquid nitrogen or whatever it will still have more logic between clock latches than an Intel processor does. That deeper pipelining means that Intel will be able to clock higher than you can for any given process/voltage/temperature combination. Apple has some very talented CPU architects and I'm sure they could design a high performance chip. But it won't be the same one that runs in iPhones.