here are two different peter bucks erroneously merged:
this peter buck is not the cellist playing in narciso yepes album:
who should be this:
Hi @Niccolo_Terzi. I can’t see a Peter Buck credit in our metadata for this album, so I’m guessing that’s coming from your file tags. Do you have any other (cellist) Peter Buck credits in your library? Anyway, it seems that Roon has matched this credit to the R.E.M. artist (which may have been the only Peter Buck in your library when this album was added). I think that you will need to make an edit in your library to correct this.
if he’s not in your DB credits, it must be in my files tags. and i do not have another album with the same cellist (as far as i am aware of)
edit means:
-manually remove links to REM artist
-add link to a newly created artist Peter Buck
i can do it (i guess), but… how it comes that roon matches an unknown artist (in its DB) to another known one? in general, i would say that roon should create an empty artist page (just the name) for the unknown artist, and not trying a guess…
Yes.
It’s a best effort scenario. Most of the time, this is the correct thing to do; unfortunately sometimes it’s not. Actually this highlights the weakness of all non-ID-based tagging systems.
I disagree on that since it’s simply wrong.
I stumbled across more but just a few combinations where the linkage between artist and an existing album clarifies this more accurate but what roon does here. I also pointed out that even your (roon) beloved metadata provider Allm… got these things right while roon fails.
To fix such miseries isn’t as easy as described.
I detected that roon added 2 albums to an unknown artists. But this isn’t 1 artist, it’s 2 differnt ones both unknown to roon.
If you then add a new artist identically named and want to link on the albums to this newly created artist you get a representation where 2 identical artists are shown, both without artitstart and you can’t easily say which one’s which.
But I agree on to your sentence about the ID-based things. Should I point out that it would be as helpfull to see the roon internal id’s to get the issue solved desctibed below? Since without it’s a real pain. I thought I’m done since now both identically named unknown artists have 1 album each as it should be.
But when I look at the artist, the other album still does appear under the ‘Appearances’ section. So I must have mixed up the ‘artistname’ at one stage where I should have better used the other equally named ‘artistname’. 
and it’s pretty hard to find out at which stage I made this mistake since all names are identical.