My pain is bi-lateral. Right is worse than the left.
I had neck pains and associated headaches for 10-15 years though there is nothing in the neck that shows on tests. No stenosis or herniated disc.
I suppose that all my symptoms can be explained by muscle spasms somewhere in the neck. Depending on which muscles spasm, I get pain in different places.

At this point most of my pain in the shoulders and arms is gone (unless I do too much computer work). However, occipital pain is not. Edgelow does not seem to help with that. Various neck stretches are helping a bit.

I don't think I have a problem with scalenes substituting for the deep neck flexors. My scalene problems are mostly from improper breathing. Training myself to breathe properly unloaded the scalenes and helped the nerves start healing.