Arsenal are a strong team, but the EPL is the most powerful and most difficult league in the world, so when it comes to the top-3 or even top-5, everyone realises that the competition will be very high, and if we talk about the championship, you need to not lose at all since the beginning of the season and keep the bar at the highest level. That's why I'm not surprised to see Arsenal in the top-2, or as it happens in the 3rd place, because it's a high result, on par with winning the title in any other league.
Arsenal is familiar enough with the 2nd or 3rd place on premier league. I won't be surprised if they finish in that position in this session. We often to hear that Arsenal is stronger at the beginning of session, and then they become weakened after middle of session because their strategy didn't change very much so that can read easily by an opponent. I think Arteta and the squad must be realistic if they can't get the trophy again for this session. I don't hope too much for them on Champions League, because they will face Real Madrid in the quarterfinal final where predicted many people will be knocked out in that round.
I agree with you that Arsenal will drop further down the table, I wouldn't be surprised at all because in the past they have been great in the early stages of the league but have been poor in the latter stages. If they face Real Madrid in the quarter-finals, it will be even more challenging for them to reach the final. I already guessed that Real Madrid should be ahead of the rest of the teams in terms of winning the trophy because they have been consistently showing impressive performances. Atletico Madrid were one of the best teams in the Champions League, losing on the penalty shootout and being eliminated. It was great for Real Madrid to win.
They haven't been in a great position since the beginning of the league but they have been playing well over time.