Not sure how Arcanine has/had better moves than Ninetales, but if you'd have to pick one, then go with Ninetales. However, these Pokemon can be used as a 1-2 punch in a Sun team, which a lot of people overlook. Arcanine's Morning Sun works well off of Ninetales' Drought ability and can help him recover from Flare Blitz. If both, Ninetales & Arcanine are built right, both Pokemon can not only cover/conquer their weaknesses, but cover a lot of ground in beating a lot of different types of Pokemon. Normal, Dark, Fire, Water, Rock, Ground, Electric, Bug, Grass, Ice, Psychic, Ghost, and Steel Pokemon can and most likely will fall victim to this "team." So, I know the question asks for 1...and not to answer a question with a question, but why not both?