Hey @Niccolo_Terzi – I’m a little confused, but maybe I’m just missing what you’re asking. It’s possible we are conflating Album Artist and Primary Artist links.
Album Artist in Roon has no order or sorting, because it’s a single piece of information – a simple text field stored with the album. It could be “PJ Harvey / John Parish” or “John Parish / PJ Harvey”, and this can come from your tags, or from Roon’s metadata, or from edits you make in Roon.
Primary Artist links are a big part of what makes Roon’s metadata different, and more powerful. These are also editable at the album level (meaning they can be added or removed), but there’s no way to sort them or choose an order right now, since these are just links to people. Feel free to open a Feature Request for this.
We generally assume that if you want an album’s “artist” displayed with certain styling, that will happen in Album Artist, which is how we sort albums in the browser. That’s why it’s a simple text field, so you can easily choose between:
- Louis Armstrong / Ella Fitzgerald
- Ella Fitzgerald / Louis Armstrong
- Louis Armstrong and Ella Fitzgerald
- Louis Armstrong & Ella Fitzgerald
- Louis Armstrong + Ella Fitzgerald
- etc
Again, ordering the links is something we could do, but that’s more of a presentation question. The distinction between Album Artist and Primary Artist links is about preserving information about the album and the context in which this music was released.
We really try to avoid concatenated performers like you often see on TIDAL and elsewhere. In the album above, an artist we’re familiar with (PJ Harvey) listed her name on the cover as “Polly Jean Harvey”, and unfortunately we don’t have that listed as an AKA, so we didn’t match this up. In many applications we would have a few choices here – create a new artist in your library (Polly Jean Harvey), or ignore the artist’s intent (just use PJ Harvey).
Because Roon treats these concepts separately, you can choose exactly how you want the album listed, and you can also find the album on PJ Harvey’s page, and on John Parish’s page as well.
In any event, you can set Album Artist to whatever you want it to be, but right now we don’t support sorting of Primary Artist links.
(btw you’re 100% correct @soundserge – Main Performer is for tracks, not albums 
thanks, I edited)