Preferring the Premier League doesn't mean Arsenal have to forget the Europa League, because as long as Arsenal are able to get good results for both of them this season, it won't be wrong to do so even though it won't be so easy for Arsenal. But I see that there are better developments in the Arsenal team this season so that Arsenal will definitely be able to fight for those two very good trophies (the Premier League trophy and the Europa League trophy).
Can Arsenal kill two bird's with a stone
Maybe they can but not with the premier league and Europa league
They need to put in more work so they can at least win the league
Anything can happen if Arsenal are able to maintain their quality, after successfully shaping their squad to be better than in previous years, Arsenal are ready to compete to kill the birds in front of them. Arteta's role was very influential on Arsenal's appearance, he as a strategist in the Arsenal squad could not be careless in his throws, birds had to be dropped one after another to reach targets that they had not gotten for a long time.
Anyway, when there is an opportunity to be able to progress better with the expected results, then of course they will continue to maximize the opportunities in the moments they get. There is no term Arsenal has to choose one of them, unless there is no more hope for Arsenal between the Premier League and the European League, then Arsenal will probably choose one of them to maximize.
But so far, Arsena's chances are still very open and therefore, it would not be right for Arsenal to only focus on one of the Premier League or the European League.
Basically, Arsenal do have a good chance this season, but I personally think that when one or several of Arsneal's main players are injured, it will immediately have a negative impact on the team's performance.
So yes, I can assume that if Arsenal's main squad is still doing well or staying healthy during this season, then Arsenal's chance to win the title is very likely to happen. But if one of Arsenal's main players get injured, then I'm not entirely sure Arsenal will be able to win the title.