I’ve just been adding this Brighton UK based blues band’s CD I found today to the database and found that there were credits for a Sean Delph and a Slim Lightfoot, turns out they’re the same person. Sean is the legal name, and Slim is the performance name.
I’ve linked the two together with a Performs as relationship but I wondered if its worth there being two entities or if they should just merged?
i prefer that they are two entities.
some artist have multiple “performs as” especially when they perform in multiple genres.
if you would then merge them it just becomes one big mess, espacially when you add an event where that artist plays.
I think you can always link artists to events with “credited as” this that name, if needed.
But I have no opinion on merging this one, or not.
I don’t mind either way - imo it only becomes a problem if (as a common example) an album previously released under the name “Sean Delph” then goes on streaming services as “Slim Lightfoot”. Then it becomes clear to me that the artist sees the names as interchangeable, and I merge.
I’d keep them separate as others are saying. An artist that I enjoy (Adam Young - MusicBrainz) has released music under multiple different project names (Owl City - MusicBrainz being is most popular and longest running) and in MB, he is broken up into different artist, but are all linked together.
My general rule is - if they only have the one performance name, I merge them and use aliases. If they have multiple identities, I separate them.
I’d likely merge these if he always performs as Slim. Mainly from the point of view of having his catalogue of work together.
As is evident from the thread, there are lumpers and splitters in the community, so you are good either way. There is some consensus that merging is warranted if the person is only ever using the one performance name. So I guess you need to wait until the person is deceased to make sure they never adopt another performance alias and then merge.
I don’t see anything assigned to Sean Delph apart from some composed/wrote relationships for songs on this 1999 album by Swamp Things. The back of that album credits him as Slim Lightfoot. Assuming that he isn’t doing anything else where he’s credited by his real name (Discogs doesn’t list anything recent and my Google searches didn’t turn up anything either), then I’d merge the legal name entity into the performance name entity.
so that is the release I have in my possession currently, a bit of a Facebook search found his profile (under his legal name) which was he was then tagged in a public posts by a Brighton based promoter sharing some photos of old gig posters of which one was for : Tandy at The Lift - MusicBrainz which mentions a “J.P. Delph & The Might Fine” but I can’t find anything more on them, but that is sharing the surname again… 
Interesting! Seems tough to tell if J.P. is the same guy as Sean or not. This Swamp Things back cover has a production credit for J.P. alongside performance credits for Slim Lightfoot. Discogs has sadly scaled down the booklet scans enough that it’s hard to know if the text there has any more clues.
I’d still merge if the Sean legal name doesn’t seem to have been used for anything beyond writing credits. I’ve gotten many more yes votes than no votes for merges in similar-seeming situations. 