Ok, you couldn't be more wrong if you tried... so please stop trying. You simply don't know what you're talking about, okay?

The PS4 Pro has a CPU that runs SUBSTANTIALLY faster than base PS4, nearly 500Mhz faster, going from 1.6Ghz on PS4 to 2.13Ghz on Pro. That's a 33% boost in CPU performance alone, which is what PS2emu makes use of, let alone the increased GPU power which is effectively doubled. The GPU went from 18 GCN units to 36 GCN units, and a clockspeed bump from 800Mhz on GPU to 911Mhz.
Who "told" me Pro runs faster than Normal? E V E R Y B O D Y. Go and read any one of a thousand benchmarks and reviews of the Pro to see the performance increase in "Boost" mode, not to mention games like FFXV which run 20-30 on PS4 but 30-60 on Pro.
The additional CPU power is what PS2emu relies and it makes hard-to-emulate titles run better. Try and play Tekken Tag Tournament or Darkstalkers Collection or Alpha Anthology on a base PS4 and then play them on a Pro to see the difference.
It has absolutely nothing, NOTHING, to do with storage and both consoles are *not* the same
~edit~
I apologise if this came across as snappish, it wasn't/isn't meant to be. Just definitive.. the machines are very different and whoever told you they are the same, lied to you. Big time.