I don’t think it’s a matter of the iPad being more Pro but the software being more Pro. I’d love to see Final Cut or something like it on the iPad. I’d also love to see the file system improved and external hard drives supported. I think in due time Apple will greatly improve iOS on these things. It be short sided to say Apple will just leave iOS as is and the iPad Pro is just a Pro iPad cause of the hardware. It needs to be both hardware and software.
As for the surface it’s a great hybrid laptop but it’s not so great in terms of a tablet for touch.