We are currently in a 2-deck format where heroes and salamangreat seem to be way better than everything else. In tournaments they are taking around 70% of the Top Cut spots, which is why there are no decks in Tier 2. Even so, some Tier 3 decks still stand a chance (even though it's very hard to build a deck that's solid into both HEROs and Salamangreat). I would argue Salamangreat is stronger than HEROs, because the matchup is usually favored for Salamangreat (as long as HEROs can't find techs to handle their initial play and follow-up)
This is pretty much the definition of a 2-deck format, as everything else struggles and has to either get lucky or benefit from suboptimal play/decklists from their opponent to have a chance.
Tier 1
TPC Comments
HEROs are still the most-represented deck in tournaments, and that's because of their free Loading... and extra bodies that can be summoned every turn. In the matchup against the other Tier 1 deck in Salamangreat, it mainly depends on how the HERO player uses their additional resources, especially their Super Poly.
HEROs currently seeme to have swapped to builds that play Loading... , Loading... , Loading... and Loading... alongside multiple Loading... and sometimes a copy of Loading... (which is a very effective 1-of against Salad [basically forcing them to skip their turn and hope to survive] but not good into the mirror). The other cards are mainly to circumvent Salamangreats ability to play through backrow by trying to guarantee surviving their turn two for an OTK on the crackback. This, of course, is not a foolproof plan, as Salamangreat can comfortably set-up its two in-engine interruptions and gain LP with Loading... in the Batle Phase to try and insulate itself from the retaliation OTK.
Recently, some HERO lists have started playing monsters that stop attacks, such as Loading... and Loading... . These cards offer several benefits. Since Kiteroid activates from the hand and Necro Gardna from the graveyard, they can't be forced by cards like Loading... or Loading... . Even if Necro Gardna is forced by Loading... or Loading... shuffling the Graveyard, you can chain it in response to still stop at least one attack. Additionally, both cards serve as good discard fodder that can punish opponents for going all in on an OTK push.
Another tech that has started seeing some play is Loading... , as it essentially acts as a turn skip against Salamangreat. However, it's typically played at only 1 copy since it's not very effective in the mirror match.
Salamangreat has the easier Skill activation condition, which makes it super consistent while still running a ton of staples. Also the deck can play around backrow going second by using Loading... and Loading... . The deck has several options to deal with any deck (which varies with player choice), and since Loading... is guaranteed every time, it's the most consistent and adaptable deck in the meta.
Salamangreat feels a little better than HERO currecntly, as HERO builds have switched up to be very anti-Salamangreat (which makes their mirror match worse), while Salamangreats' techs are fairly universal against both the mirror and the field. Techs like Loading... / Loading... are invaluable against both the HERO and Salamangreat matchups.