You cant site just logs, because all the best players are playing fire, meaning with 3 specs that are somewhat close, fire would come out no matter what.
If every single top player was arcane, then you'd see arcane doing a lot better in logs compared to the other 2, still not the top in all scenarios by any means, but you cant just use logs for that reason, because it's pretty bias.
I don't dispute fire is better. But 7.1.5 is different