Yes, they both have the same and Intel cores are known to be bigger than AMD and Apple cores but poor in area/performance.
So I'm not sure what your original post about smaller cores is all about considering that the A18 Pro CPU is almost certainly smaller in actual die size.
It's not about die area at all. It's about the SSD and chipset and WiFi etc. each using power on top of what the CPU uses, and ending up as a much larger percentage of system power draw for a 15W CPU than for the same system with a 60W CPU that has around four times the multi-thread performance by having four times as many of the exact same cores.
You lost me.
Maybe you can articulate what you're arguing from the start?
Suppose you have a system that under some workload will draw 10W to run the chipset, WiFi, SSD and so on and another 15W to run the CPU, so that it's 25W in total. The 15W CPU has X number of cores and gets a score of 1000 on some benchmark. Performance per watt is 40 points per watt.
If you put 4X of the same cores in the same system then the CPU uses 60W, the WiFi etc. still use 10W, so the whole system uses 70W. It scores 4000 points and the performance per watt is 57 points per watt. You got four times the multi-thread performance and performance per watt went up.
That's why any CPU reviewer worth their salt will isolate CPU power.