As I look at these tier lists, I am noticing two things that bother me. I certainly am not an expert in any regard, so if I have any misinformation, please let me know.
Why is Yoshi so low? I would put yoshi right about 14th, somewhere around there, perhaps a bit lower, but I don't see how Yoshi is worse than Ganon. Yoshi has combos, he can move decently fast, hes got the parry, superarmor, doublejump cancels. Eggstalling is a fantastic tool for getting back from the edge. He is really heavy, any good Yoshi can usually live well past 100 percent. He certainly has a lot of drawbacks but he has a lot of really good tools that characters like Ganon don't have.
Also, I have seen people grouping Pikachu with the other s tier characters like falcon and puff. Why put Pika so high? I would agree that he is just below the S tier characters, something like 10th place, but he loses the neutral to every top 8 character except Falcon, and that's not winning, it's only an even matchup. Pika is awful against sheik and ICs, meh against spacies and marth, has a hard time against puff and peach. Even among the mid to lower tiers his matchup spread isn't too great. If you're basing it on tournament wins, of course axe would heavily influence the results, but that doesn't make the character S tier.