Just because a team is rated as Tier 1 or 2 doesn't mean anyone who takes them to an event is automatically going to perform better because of it. Setting aside how often I see this play out in my gaming group (there's a Goblin team that's outperforming multiple Tier 1 teams in my league), we as a gaming community routinely see this every edition in 40k and AoS as well - a faction gets an update that makes it play incredibly well at an event, driving up hype that the faction could play similarly well at the next event (despite people jumping on that bandwagon not really understanding what made them perform as well as they did), only to set them up for disappointment in the end when their "strategy" doesn't pan out the way they thought it would. And that's provided that the people showing up are there to win games at all costs and aren't there just to roll dice and have fun. It actually wouldn't even surprise me in the slightest if the teams that played the fewest number of games were over-performing on account of player skill alone.