nonamethanks said:
To me "artoria pendragon alter" makes it sound like the tag is for a variant of Saber Alter. It doesn't feel like these renames are going to achieve any substantial difference. Singling out "lancer alter" as a single qualifier at least makes it clear that it's Fate's evil version of artoria_pendragon_(lancer)_(fate).
Speaking of which, thinking about it artoria_pendragon_alter_(swimsuit_rider)_(fate) should probably just be saber alter (swimsuit rider). I don't remember why it was decided to not just name this tag after Saber Alter given it's literally just her in a swimsuit.
Probably the same reason why we have it as artoria_pendragon_(swimsuit_archer)_(fate) instead of saber_(swimsuit_archer)_(fate), aka probably weird oldbooru semantics regarding FGO character classification and umbrella tags.