Perhaps I'm not being clear in what I'm saying because I'm pretty sure that there is a difference. For example, two members of Walk Off The Earth have released some singles under the name Gianni and Sarah. When I entered them into the database, I created a new artist by that name. I later merged Gianni and Sarah into Walk Off The Earth after discussing it with the band's management company. When I did the merge, I did not rename the artist credits.
In Picard, if I leave the "Use standardized artist names" option unchecked, both the artist and album artist tags are Gianni and Sarah, whereas if I check the option they are both Walk Off The Earth. If I had done the merge the other way (Walk Off The Earth into Gianni and Sarah), then the tags would always show as Gianni and Sarah, regardless of the "Use standardized artist names" setting. Of course, this would now change the artist and album artist tags contents for releases by Walk Off The Earth.
I actually ended up developing a plugin for Picard to provide both standardized and credited artist names because I had a need for both in my file naming script.