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.