Bayonetta: 476.5
Cloud: 475.75
Diddy Kong: 377.5
Sheik: 325
Fox: 278
Sonic: 270
Mario: 202.25
Rosalina & Luma: 163
Zero Suit Samus: 163
Mewtwo: 154.5
Ryu: 132.75
Captain Falcon: 122.75
Meta Knight: 101.75
Greninja: 87.25
Peach: 79.25
Pikachu: 78.5
Ness: 75
Luigi: 74.25
Corrin: 73.75
Marth: 70.75
Donkey Kong: 68
Toon Link: 61.75
R.O.B.: 58.25
Lucina: 55
Mega Man: 48.5
Samus: 39
Shulk: 37.5
Villager: 36
Yoshi: 34
Bowser: 32.5
Lucario: 32.25
Lucas: 32
Olimar: 32
Ike: 31
Roy: 30.75
Mr. Game & Watch: 27
Wario: 24
Link: 20.5
Little Mac: 16.5
Duck Hunt: 16
Falco: 13.5
Wii Fit Trainer: 13.5
Pit: 13.5
Charizard: 13
Robin: 11.5
King Dedede: 9.5
Ganondorf: 6
Palutena: 5.5
Bowser Jr.: 4
Zelda: 3.5
Dark Pit: 3
Dr. Mario: 1.5
Pac-Man: 1
Kirby: 1
Mii Gunner: 1
Jigglypuff: 0.25
When you look at that list, I bolded all of the characters that are over 100 points plus Marth and Lucina, since we were talking about whether Marth (and by extension Lucina) is a top tier or not. When looking at the characters with over 100 points, Marth and Lucina are much lower than that. We need to remember that tournament results aren't everything. However, these results do show that certain characters do better in tournament and thus are most likely stronger overall. Again, tournament results aren't everything but it's a good starting place.
Secondly, let's go over max potential of the top tier in general, their best and worst matchups, and see if in my opinion they'd be in my personal top tier on my tier list or not (a source for matchup chart compilations:
https://www.reddit.com/r/smashbros/comments/7b0tx4/notable_players_matchup_chart_compilation_v7/ ):
Bayonetta- Has the best tournament results right now. Concerning matchups, there seems to be a consensus among top players that Diddy Kong is Bayo's toughest matchup, and might be the only one in which she loses against. Sheik does ok against Bayo, but that one is closer to even than the Diddy Kong one, where Diddy most likely wins. ZeRo is still the best player in the world, and he's able to still beat Bayo mains consistently with Diddy Kong. I've seen people say that Sonic and Marth/Lucina do well against her, but those results haven't been consistent enough yet. She has incredible strengths, with her few weaknesses being that she's light, is tall, and relies on witch time and her air game to land KOs.
Cloud- 2nd best results, mainly due to sheer popularity, how easy he is to pick up, and his sheer amount of great strengths. However, his large frame and terrible recovery are very blatant weaknesses. Pikachu and Sheik are two characters that have incredible edge guarding potential, and Cloud most likely loses against those two characters. ZeRo was also able to do very well against Anti when he counterpicked as Cloud in a national that happened a few months ago.
Diddy Kong- Consensus is that Rosalina and Mega Man are his toughest matchups, with occasionally Mario being tough. Other than that, Diddy tends to go close to even with or win any other matchup. He's notable for being a good counterpick against Bayonetta. His recovery is average and his banana peel can turn the tide of a battle. Even still, Diddy has a ton of strengths and his weaknesses are harder to exploit, even if he's not as popular as Cloud.
Those three are the most popular characters at the top level and get the most consistent tournament results by far. I would say that Bayonetta, Cloud, and Diddy Kong are certainly the top 3 in top tier. After that, you get a bunch of others:
Sheik, Fox, Sonic, and Mario all get consistent tournament results still, but much less consistent than the top 3. Sonic tends to do better in Japan than America, specifically. Rosalina and ZSS have been getting more consistent at the top level lately, and Rosa has some really stupid good moves (such as up-air and Luma) that make her shine. As long as the opponent isn't using Cloud or Meta Knight, Rosalina mains tend to do just fine. Mewtwo and Ryu aren't as popular as some other characters, but still have insane moves that cause them to be threatening in many matchups. Mewtwo's fallen off slightly recently due to Abadango picking up Bayo, but he's still a good character. Out of the bolded names, the ones I think that miss out on top tier for sure are Captain Falcon, Meta Knight, Marth, and Lucina. All four of them have worse tournament results than the others under Das Koopa's system, and have tougher matchups overall. Marcina does ok against Bayonetta, but Diddy Kong can be a royal pain and Cloud can be an uphill battle. They also struggle against Sonic. MK and Falcon have tough matchups of their own against the top tier. Examples would be Meta Knight struggling against Mario and Falcon struggling against most of the best characters in general.
In short, here is how my personal tier list shapes up at the moment:
Group 1:
>
>
Group 2:
=
=
Group 3:
=
>
=
Gatekeeper:
Just misses:
=
/
>
This leaves Marcina in 13th/14th place, most likely. Of course, this isn't the full tier list. I'm just listing off my thoughts on the meta right now related to the characters I bolded in the list.
My tournament experience includes going to locals and attending my first regional recently. So, I'm not a top player and thus my knowledge is most likely more limited than top players. However, I did my best to explain my summary of opinions and I also have at least experienced the tournament scene and done research, which helps.