Around Spring BR's last season, I tried these guys out. I never got to play them in a tourney because I got the flu, but that's beside the point. Arcanine is too inconsistent. You have to be playing some kind of recycling (I played Rayquaza/Stark, but that was flippy). Another problem is that to do big damage (which he can do) you have to be almost dead, and with Arcanine's low HP, he will die too quickly and your opponent will get ahead on prizes.
JMO.