The one thing throwing off the number is Gigantimax. My head is saying there's 10-15 of them, but I don't know if those eat into Galarians.
All in all though, when we use the full number of new mons, it has to be a combined total of brand new, galarians and gigantimax.
All in all though, when we use the full number of new mons, it has to be a combined total of brand new, galarians and gigantimax.