Has anyone out there found examples of solid UX career path definitions with roles?

As most of you probably know, job titles, roles, and responsibilities in the User Experience field are often ambiguous or suspect at best, and a total mess at worst. It doesn't help that most HR listings don't even include UX as a category, it almost always gets wedged somewhere under engineering.

To that end, as we define and develop our enterprise UX team we want to create sensible, intelligent career paths for both management and non-management trackx, allowing individual contributors the same leveling opportunities as management track people. Ideally this would also allow people to move back and forth between these tracks to let them determine where their strengths lie without committing forever to a single track. Also, terms like Sr., Lead, and Principal can get swapped and conflated, making for a very confusing "path."

IBM and some other companies have parallel tracks for managers and ICs, but I can't find examples anywhere. I've found various diagrams attempting to define a UX career path, but sometimes they contradict each other, many are too specific to one discipline or another, and almost none address the 2-track idea:

I think the closest I've found so far is this one, which addresses the issue of different proficiencies in different tracks, but even this does not address really parallel tracks:

What is your experience with this? Do you know of any other models you can share? Do you work somewhere that has this solved? Please share your insights into this!