JD, yes the rotors can definitely be the culprit. I went through the same frustration when I replaced my first rotor set about 16 years ago.
Finally bought different rotors and the problem was instantly fixed.
I've used many brands of pads/rotors over the years, and never had the problem again. I actually stored those guilty rotors in the attic for several years, and they got a nice light rust coating. I used them later and they didn't squeak at all - go figure.

You generally don't turn the Benz rotors, just replace them with every 2nd or 3rd pad replacement. They do tend to wear quickly - about 40k miles.
If the current rotors are new, and you want to turn them to stop the squeal, then be sure they don't take much off. The min thickness is stamped on them.

To get them off, you must remove the bearing hub, chuck it in a big vise, and unbolt the rotors from the back side. Not too tough, and pretty straightforward, you just need to keep the bearing grease very clean by taping up the openings, or repack the bearings when you reinstall the hub. There should be a writeup in the diy section somewhere.

DG