If you want JPGs to look different, you can change them in the camera, and RAW files are just that: raw. They will vary between cameras slightly because the cameras have different sensors. Editing RAWs from 5d3 vs. 5d4 vs. 6d (my only experience) is not very different. Ultimately, the workflow that matters is a photographer capturing the image and getting the output to the studio quickly, in high quality. Event photographers often tether via ethernet or USB and the studio can post-process the RAW in minutes (or even seconds). The part of this that is most sensitive and hardest to recover from error is the photographer capturing the image, which is why consistency and usability of camera controls is so important.

IIRC none of the EOS DSLRs had focus peaking from the factory, you need Magic Lantern -- Canon didn't program it at all.

My point about JPGs is they will look different between cameras anyway because of software differences, with the "same" settings, so they're already inconsistent from the user perspective. Editing RAW is not necessarily different but from what I've heard that's because RAW editing software busts its ass to try to correct for all manner of arbitrary differences between camera models. It's in spite of camera design that we have consistency, not really because of.