This is not bad idea in principle however often an artist is well represented either in Discogs or MusicBrainz but not both, just look at the first page (artists are ordered by total number of releases discogs + mb) and you’ll see that in many cases there is only one release in either mb or discogs.
Go down to page 20 and the total number of releases mb + discogs is only seven
So the chances of getting three matches is quite low
I could do this if it was required to get agreement
Not fair to lump me in with this really.