Speaking of low tiers overestimating matchups, I believe pika v ganon is 5-5
Really in this matchup Pika's movement speed and ability to combo medium-weight chars, and Ganon's lack of a quick aerial (uair does alright, but doesn't have quite the hitbox needed) really hurts him in this. Ganon's hitting pikachu three times and he dies really hurts Pika, but that's mainly why it's even.
Ganon's hurtbox is huge, his aerial and ground mobility is lacking, and the majority of his moves are slow (though they cover a large area). Pika sometimes has a little trouble getting in, but his jolt and dashdance game is often enough. Once he's in and gets a grab/rising uair/whatever, Ganon is combo bait. And once Ganon's off the edge, Pika has very little trouble edgeguarding him. Jolts/aerials prevent ganon from recovering low, uair spike prevents him from recovering high. Pika has no such troubles recovering against Ganon, as the versatility of your upB makes it difficult or often impossible to cover all your recovery options, even with good reactions. Ganon also has relative difficulty catching Pika (unless he has a master ball, pokejoke!) and relies mostly on punishing pika's approaches to get damage. But the great thing is, pika rarely has to approach Ganon, he can just dash dance and throw jolts outside of Ganon's range until he sees an opening (granted yes it's then on the Ganon to seemingly create openings when there isn't really one, mindgames, but he doesn't really have much to do this with).
On Ganon's side, Pika dies early. You really only need to get like 4-5 solid hits (3 on yoshi's) and Pika is dead. Pika's a relatively small (and fast) character though, so he can get under and around a lot of Ganon's moves. Ganon can CG Pika, and a grab sometimes means a stock, it's just getting that grab is really difficult for Ganon. His wavelanding game helps with mobility some, but usually he has to jump up to a platform to do this, putting him above pika, which is often where he doesn't want to be (pika's uair is faster than anything ganon has and sets him up nicely to be combo'd, pika's usmash is brutal, etc).
From my perspective it relies a lot on Pika just being somewhat familiar with the matchup and not run/jumping into Ganon's aerials. If he does, he dies fast. But if he's patient, I don't really see much that Ganon has to shut down Pika. He's just too slow.
