Hi Magnus,
I'm not the greatest but here's my input.
the article accordion is like any other module to publich in any tempale position.
From what I see from protostar you have only a couple of positions, position 3, content and position 2. I don't know if your template will allow 'stacking'. that means placing multiple modules in one position and they will stack above each other stretching the page. The trick would be moving them around in the 'ordering' control on the right side of the module controls.
The other control to be concerned with is the 'menu assignment', where you select which menu item the module is to be published on.
And, don't forget to publish the module.
Hope this helps.