Ability to Reorder/sort the articles in Service Desk Portal

Currently, we have the ability to sort the categories and have them reflect on the portal page. 

The problem now is that the articles themselves, within each category cannot be sorted. They do not follow any discernable sort order and seem move up or down based on date last updated. 

It is important for us to be able to sort our articles within the categories, not just the categories themselves.