Arsenal has a good chance to compete for the Champions League but they are not on the list to win it or reach the finals. I suggest they should focus mainly on winning the Premier League which will enhance their chances of winning the Champion League anytime soon. Arsenal are likely favoured to win the Premier League this season if only they would enhance their performance since Manchester City is a better contestant for the Champions League, for what I know they will try as much to devote more effort into UCL other than the Premier League which gives Arsenal a bolder step to accumulate more points than City.
Expectations for Arsenal last season in the Champions League were actually quite good, especially when they performed consistently in the Premier League, to the point where many predicted they could get rid of Bayern Munich in the quarter finals. In fact, Arsenal ended the season empty handed, without a single trophy in their cupboard. This failure was very disappointing for fans, because Arteta had built a very good squad with a number of expensive players in his squad. Next season, if Arsenal perform consistently in the Premier League, it is likely that they will perform with the same performance in the Champions League, but Arteta would be better off prioritizing winning the Premier League trophy first. Because theoretically, the competition in the Premier League is more capable of being controlled by Arsenal than the Champions League, even though the number of matches is much different.