Ninetales shouldn't be Top A-Rank. I'm going to be honest: It sucks outside of providing weather. More often then not, ninetales is going to lose every weather war due to its poor typing, subpar offenses and SR weakness. To win weather wars, ninetales must rely on its teammates to beat tyranitar, hippowdon and politoed. Because of its garbage typing, it will have to switch out quite often, which is compounded by its SR weakness. I feel that its more fit for Mid/low A-Rank.
Heatran deserves Top A-rank. While its typing gives it some unfortunate weaknesses, it gives it some nice advantages. It resist Dragon, fire, ice, grass and many other important types. Furthermore, with the Air balloon and HP ice, it becomes the best check to ground types in the tier. It has an amazing base 130 special attack and great 91/106/106 defenses, allowing it to tank hits and dish back out powerful damage. Heatran has some flaws, but his pros easily make him Top A-Rank.