WordPress Post Author metabox filtered by category

Hi guys,

I am wondering if this is possible, and how it could be achieved, or if something similar already exists.
We currently have 135 different authors, and 72 different categories, is it possible to have a dynamic metabox that allows admins to select/assign post author from a “filtered” list of authors based on what category is selected.

Currently no authors are posting directly to our site, we are getting submissions via email, which then our editors upload and assign authors to that post. While i understand that this is not the way wordpress was meant to be used to create posts, we have found that we are the ones that are going to have to do it, due to different skill level of our authors and the boss wanting to have control of the content that is being posted to the site.

While we are able to achieve this, the list of authors is getting ridiculously big, and we would rather be able to just select from a smaller, shorter, “filtered” list of authors based on what category is selected.

I feel like this means we need to be able to restrict certain authors to specific categories, (by manually assigning them?) and that way, when we are creating new posts, and select a category, the list of authors gets dynamically populated.

The easiest way, you can create another user role and manage the users over there which posts/pages they should see. You can search WordPress.org for free plugins or CodeCanyon for paid one as “user role manager plug-in”