When the pokedex lists the Japanese name and the romaji doesn't match the katakata, I just scratch my head. But, I suppose if you say the official romanizations come from what names the Japanese came up with and then have to spell with katakana...it makes more sense. I assumed the Japanese version of Pokemon just used katakana, and fans came up with what the katakana must be referring to, or just mistranscribe it (ゾロア Zorua just looked like a poor ability to read katakana).The Serebii Dex has always used the official romanizations, rather than a transliteration of the Japanese characters.
Official names like Cobalon or Chillarmy etc as romainizations either make the names look nicer or cooler on merchandise, but don't always make the etymology of the names apparent while un-official ones like Wargle, Emboar, Freezio or Vulxena are to make them easier to memorize until we get real English names and also highlight where the names come from that may not be apparent when you're looking at Uooguru, Enbuoo, Furiijio, or Barujiina.
Hm, while Emboar sounds good, the "oo" might mean "king." "buoo" is a rather counter intuitive way to pronounce "boar" even for the Japanese.