I would merge them into one “Goblin” and set “New Goblin” as an alias.
Another place to see all the names together is Wikipedia.
Also on their own site they consider “Goblin” and “New Gobln” to be the same thing. Look at the Discography and you’ll see that 2013 Tour EP listed in with everything else http://www.goblinofficial.com/discography.php
I would merge releases into the New Goblin release because they are both linked to same New Goblin cover art https://www.discogs.com/release/4977136-Tour-2013-EP/images where New is small and easy to miss. Maybe it’s why there is a Goblin release.
Artists and release groups should also be merged, keeping artist credits.
He changes his name with most every release; sometimes even from track to track. Near as I can tell, it’s all the same guy. I tried to merge artists, but got voted down.