Imo, just gonna go over them briefly :
55-45
: I think Mario wins this MU by quite a lot when he's in other stages other than FD, because Little Mac is extremely vulnerable to platform camping. Basically, Mario forces the Little Mac player to go in the air (which is one of Little Mac's biggest weaknesses). And then, Mario has the perfect tools (Cape and especially FLUDD) to gimp Little Mac's recovery. However, in FD, I think Little Mac wins by a tiny bit, since not only he can pressure Mario a lot more in neutral, but he can kill Mario way early than a true input Shroyuken by Ryu. It's very hard without platforms to gimp Little Mac. I put 55-45, since we're not in For Glory. The metagame consists of other stages, not only FD (and thank god for that)!
50-50
: I SWEAR TO GOD THIS MU IS INCREDIBLY ANNOYING! Olimar is the worst ****ing character in existence. BUT THANK GOD Mario has quite the tools to take on Olimar quite solidly. I do feel it's even. Olimar does have a laggy grab, which does give Mario an opportunity to combo him. That's where the problem comes in. Olimar can't be comboed easily (which is annoying btw), since he has so many moves to escape Mario's combos. Also, his ****ing Pikmin Throw is annoying too, because it does prevent Mario's to approach safely and he will take a lot of damage of this. One big thing that Mario can capitalize on in this MU is edgeguarding, and Olimar is incredibly vulnerable since he has not hitboxes to protect himself. However, Olimar can do the same thing to Mario and he can recover pretty low (if Olimar has no Pikmins). Also, Mario can reflect Olimar's smash attacks which can lead to early kills if the Mario makes good reads (which is INCREDIBLY SATISFYING). Btw, sorry to offend some of you guys who like Olimar, but I really do hate this character. My apologies.
55-45
: THIS MU IS FUN (especially against a really good Villager)! The biggest advantage that Mario has when facing Villager is his Cape, Mario's best friend against zoning characters. Because of this, Villager has to respect Mario's Cape when it comes to prevent Mario from approaching. He can't use Lliod Rocket as much, neither his Fair or Bair just to name a few. Mario has an easier time landing kills than Villager, since the latter has KO moves that are very unsafe to use in neutral. However, there are a few things that holds Mario back from bodying Villager. First, his poor range can make it very difficult to approach Villager without using his Cape too much. Second, Mario can't edgeguard Villager since his recovery is almost ungimpable, and Villager can gimp Mario very easily. Also, Villager can nullify Mario's approaches with Fireballs since he has Pocket.
55-45
: I don't have a lot of experience against Wii Fit Trainer. So I can't really say much about her, but I heard that Mario wins this MU by slightly.
55-45
: OH MAN! THE HYPE KING! THIS MU IS HYPE! Probably the character that I have the most experience with. Let me tell you this. This MU is not easy for Falcon, but it's duable. Mario can combo Captain Falcon A LOT, due to him being vulnerable to the up-tilts juggles, and Mario can edgeguard Falcon very well, due to him having a not only poor recovery, but it's also pretty predictable. However, Falcon can pressure Mario easily and can rack up the same amount of damage as Mario in a few hits, because Falcon has better damage output. Also, he has better kill comfirms than Mario, which he has to be careful of, since Mario does have a quite hard time killing Falcon due to his weight. Falcon also has slightly better range than Mario which can hinder Mario's approach.
45-55
: THE NEW MARTH OF THE GAME! His huge disjointed hitboxes can give Mario a hell of a hard time approaching Shulk. Basically, Shulk can capitalize on Mario's two biggest weaknesses. First, he has one of the best reach in the game, giving him a huge disjointed hitboxes which Mario is incredibly allergic to. Second, since he has the Jump Monado art, he can gimp Mario pretty easily. However, what makes this MU duable for Mario, is that once Mario gets in and grabs him, Shulk is pretty much doomed. He's combo food like Falcon and Roy and no options to escape Mario's juggles, since none of Shulk moves come out fast. Also, without the Jump Monado, Shulk is pretty vulnerable to edgeguarding, which Mario can capitalize on. Mario still has to be careful when edgeguarding Air Slash, since it has huge range.
55-45
: I think it's pretty much the same thing as Villager combined with Olimar. Duck Hunt can't carelessly throw out projectiles since Mario can reflect them. Once Duck Hunt is off-stage, Mario can capitalize on it, since
45-55
: I HATE THIS MU SO MUCH, just because not G&W is an annoying character (personally), but he has a good recovery that's almost impossible for Mario to gimp and he has THOSE STUPID DISJOINTED AND LONG-LASTING HITBOXES THAT ARE JUST SO ANNOYING TO DEAL WITH (****ING UP-SMASH)! Plus, Mario can't even combo him due to G&W fall speed and weight, and G&W does since he has the best combo throw in the game (imo). Like Olimar, another character that I INCREDIBLY HATE.
60-40
: It's just like Villager MU, but a lot easier for Mario, since he can combo ROB a lot and ROB has no options to escape Mario's combos. Plus, ROB has a slow recovery and has no hitboxes to protect himself from getting hit, which Mario can capitalize on and edgeguard ROB (can even lead to death if the Mario player is consistent on his punishes).