I understand that not everyone with Job/Configure should be able to edit their job's priority.

But why introduce a permission for global job permissions independent from Overall/Administer? What's the use case for not being an admin but wanting to change global job priority config?

Well, I might be wrong but I can see the use-case where someone is allowed to tweak the Priority Setup (ie assigning priorities to groups of Jobs) but they are not allowed to change Jenkins main configuration.

This permission should however not be confused with managing the basic setup of the Plugin on the main configuration page, that is for Administer to do.

The problem seems to be worst: There is no security at all ... See https://aheritier.ci.cloudbees.com/advanced-build-queue/

See JENKINS-21313: basically, it is essential that you enable "Only Admins can edit Job Priorities" on the main configuration page.

Just found it few minutes ago (In fact I looked at the code)
Like others I'm not convinced about the no security by default ...

>> Like others I'm not convinced about the no security by default ...
No argument there. Looking at JENKINS-21313 (which I reported), I noticed my comment back in Jan.2014:

>> Is there a reason global configuration doesn't require Administer permission?
I think the reason is historic. Magnus is going to fix this, I think.

No security by default isn't ok.  I created a non-admin user with only Read permissions and it was able to add job priorities.  This should respect existing global permissions correctly.