Yah, there are embedded power processors scattered all over IBM's hardware lines. The z tape controller a couple years ago was just a rack mount POWER server. OTOH, so is x86, the z's HMC, PE's etc are just x86 laptops/servers.
But thats like calling an x86 server an ARM because there are ARM's in the disk controllers, and on the motherboard acting as BMC's/etc.
But thats like calling an x86 server an ARM because there are ARM's in the disk controllers, and on the motherboard acting as BMC's/etc.