We have a very similar situation. We have a series of training articles for our agents that we would like presented in the Knowledge Base in a specific order. We had thought to sort by the Order field which would allow us to assign a numeric value to each record 1,2,3,4, etc. This method has worked great for us on other tables. But unfortunately, we have been unable to find an order field within the knowledge article table.

As a workaround, we created a master knowledge article that contains a bulleted list of links to our training articles which we organized in the order we recommend agents review them. Then we just share a link to the master KB article with agents.

Using this method you could associate the master KB article on your portal.