Template files for multiple slugs/id's

Hi everyone,

In the site I’m building (Sage 8.5.1), there are three prominent categories which makeup the base of the site. Beyond that, I don’t want to break the standard display for other categories and archive pages. All three special categories will share a template.

My problem is keeping it DRY. I can easily make three template files, one for each category slug, but the content will be identical. Is there a way of having a template which is used for multiple archive slugs or IDs, a meta-category, if you will. This would be trivial for single posts or static pages, since the Sage template system is right there, but one can’t configure archive pages in the same way.

My best guess so far- create the three slug specific pages, and have each of them pull a common template file, much like single.php does