I don't see where you get the "chooses names precisely" part from. They are all typical German/Welsh/Norse names to me, besides a few made up ones such as Gough. Gehrman is literally German with an 'h' in the middle, Ludwig is a very common European name, and I can remember a very few location names which are actually made up such as Anor Londo, Eleum Loyce, Izalith, Shulva, Cainhurst and Irithyll, off the top of my head. Lordran and Drangleic sound like low effort, cliche sounding names. Dark Souls 1 had location names which were simply description of the areas like Ash Lake, Undead Asylum, The Depths, same goes for most of Bloodborne and DS2. Not dissing the naming here, just wanted to know where you think that Miyazaki actually put work into naming his creations with the associated etymology, because I believe that he just chooses fancy names which sound like they'd reflect the character or location's personality more than anything else (imagine how weird it would be to switch Sif and Kalameet's names). More than anything, I believe he probably found Arianrhod an interesting name and he decided to call the new location Ariandel and it has probably nothing to do with Beautiful Silver (although Beautiful Silver could be interpreted in a LOT of ways, it could even describe Yorshka or Irithyll if it were in the base game)

/r/darksouls3 Thread