I think you need better odds for Arsenal to finish in the top 4. With Pochettino, Conte, Klopp and even Ranieri going after the top 4 and Arsenal's lack of better striking options over Giruod, they would have a really hard time getting in there this season. I'm not even mentioning Pep and Mourinho yet and it's already a hard proposal for Arsenal.
Arsenal finished last season in 2nd place despite Tottenham was leading all the time until last week. I don't remember any season Arsenal didn't finish in Top-4, basically they are dominating the league even though they couldn't be champion. I remember 10 times or more they qualified to Champions League in a row and you can't go CL if you are not in Top-4.