Here's some actually unbiased power rankings..
Team Overviews:
Freedom Farfetch'd
Finchinator, devin, 52Gambit, PinkDragonTamer, Skysolo, Colonel M, Monsareeasy, perfect minun, Trade, Skoun, maroon, GreenGogoatttt, 64 Squares, m00la
This team definitely has one of the better lineups; players like Finchinator, devin, PinkDragonTamer, and Skysolo are sure to do well. Other players like Skoun, Maroon, and 64 Squares, if he plays his games, should do fine if properly supported. However, that is where this team falls a bit flat, in my opinion; it is not clear who their National Dex OU support is. I, however, do not see any other stand out picks. This is also the team that took COLONEL M AS THEIR 6TH PICK. I don't mean any disrespect to Colonel M by that, but he has not played Pokemon in like 2 years.
Overall, I think this team is pretty interesting and has some very solid players, but a lack of clear support slots leads me to believe that this team will not do that well. Happy to be proven wrong though!
Slateport Absols
Chazm, BaconEatinAssassin, Niadev, Vaboh, arifgoku, Splash, Nevelle, RaJ.Shoot, Roginald, Shadowmonstr7, TacticalFacepalms
This team is cool. Chazm has a pretty interesting take on the National Dex OU metagame, though I tend to disagree with those quite often. Regardless, that should not stop him from doing decently well as a player. He will provide good support for (what I think will be) his other National Dex starters in Vaboh and Splash, which can't be undervalued. Chazm also managed to pick up BaconEatinAssassin, who is perhaps one of, if not the best options to slot into the Best of 3 slot. BaconEatinAssassin has a great grasp on the National Dex AG and National Dex metagame, and if he puts some effort into learning National Dex UU together with Niadev, then I can definitely see him going undefeated.
I don't really know enough about the rest of the players, but Niadev knows National Dex UU very well and Nevelle is fine at National Dex Anything Goes from what I've heard. I think this team will do okay; their main downfall is how reliant they are on just a couple players for support.
Chicago Krookodile
Sevelon, Maki, Sabella, !!11!1!!, martha, Unicorns, Djokra, Avaritia GC, Yami, Kaitlyn, Aurodian, Airwind, Stareal, DerpyBoi, NuttyRabbit
I think this team's lineup is the strongest out of any. Sevelon is a good National Dex OU player and will be able to support other players well, while picking up a very solid record himself. Stareal clearly has the drive to do well, managing to qualify for OLT, and other players like Sabella should do well if they care enough. !!11!1!! is, in my opinion, the best National Dex UU support. Together with martha or Maki, I reckon they will do well in National Dex UU. Unicorns and Alice are decent players overall and will probably manage to do fine too. Kaitlyn will probably be slotted into their Best of 3 slot, where I have doubts of whether they will do well or not. Other than that, Sevelon managed to pick up Avaritia GC, Aurodian, and NuttyRabbit, who will be nice additions to fine tune their teams. Players like Yami, Airwind, and DerpyBoi are honestly questionmarks for me, but we will see how they'll do I suppose.
In case I didn't make it clear in the first paragraph, I believe that this is one of the best teams. They have very solid players in Sevelon, Maki, Sabella, and Stareal, and sufficient National Dex OU support. They also got the best National Dex UU support in !!11!1!!. The only issue I see is their Best of 3 slot, but I believe that this team is for sure a playoffs contender.
The Pleasednuts
Micaiah, DNNP, Fardin, PA, LuckOverSkill, Niko, Geysers, zugubu royale, umbreon098, Averardo, H.M.N.I.P, Renny
This is what happens when you let someone draft FILO. With Micaiah taking the lead in National Dex OU, I think he will manage to put up a solid record together with players like zugubu royale and Niko. Fardin is arguably the best Anything Goes player in this pool, but he might have to be slotted into Best of 3 with Geysers taking the wheel in Anything Goes. Regardless, I can't see him doing any worse than 4-1 wherever he is slotted. Averardo has also been playing National Dex UU and will probably manage to do pretty well. The only questionmark I have is their second National Dex UU player. It could be PA, DNNP, or perhaps Micaiah decides to shake it up through putting zugubu royale into the tier.
I rate this team and think they will do pretty well depending on how well some of their players manage to pick up National Dex OU and National Dex UU as the tournament progresses.
Stalwart Skarmories
SputnikGT, faded love, HoodedZack, N_Mareanie, trace, temp, Solaros & Lunaris, Bread Sandwich, Maple, EviGaro, Sagisolar, pileosand, Ho3nConfirm3d
This team is interesting. SputnikGT is solid at National Dex, and together with faded love, HoodedZack, Solaros & Lunaris, and Sagisolar, they will have plenty of options in National Dex OU that can do well. N_Mareanie is the best National Dex UU support option right behind !!11!1!!. He knows the tier like the back of his hand and is a decent player. Together with temp, they should do well in National Dex UU too. Bread Sandwich is likely their National Dex AG starter, but I am not entirely convinced of how well he will do considering the rest of the pool. Their Best of 3 slot I reckon will go to trace, where if he is motivated enough to put effort into his prep and familiarizing with the tiers, he is definitely going to do pretty good.
This team is solid. I do not think it's quite on the level of the Chicago Krookodiles, but they should be fine.
Pogging Pexs
Chloe, xavgb, Zneon, Jordy, Lilburr, Drud, Ruft, SHSP, WSun1, Saladae, I Eat Snoms, ShionShadows
I won't speak too much on our team, but I believe it's pretty good overall.
Overall Rankings:
1. Krookodiles
2. Skarmories
3. Pexes
4. Farfetch'ds
5. Pleasednuts
6. Absols
Ofcourse, you should take this post with a grain of salt; these are merely my predictive thoughts on how everyone will do after looking at the rosters. I am very open to be proven wrong by teams!