InkWizard - What you want is not a fix for something broken, but a new feature.

Both of the pages you describe are category/subcategory listings, yet you want them to use different templates. That can be done; it will require some additional coding to distinguish the page involved and rework the column/row layout accordingly. It would be nice to use the per-page template override system, but both of the pages are named "index" so they can't be distingushed that way. You could make a copy of the alternate file for each category, but that would get very cumbersome to maintain.

The best way will probably be to insert the distinguishing and alternate layout code in
/includes/modules/your_template/category_row.php.