Hopefully arsenal will manage it to pass the group stage. Arsenal has got the easiest group. Lens and Sevilla played so badly in the domestic league. It can give arsenal a chance to dominate the group stage of UCL. Arsenal just need to be careful with sevilla.
I expect nothing from lens but sevilla is still a threat for arsenal. Sevilla played poorly, but still won the Europa League last season. Arsenal, on the other hand, didn't make it past the playoff stage.
Sevilla can comeback anytime. Arsenal shall not underestimate sevilla which was winning europa league trophy last season. Even though a lot of important players already left from sevilla but this can also be a threat for arsenal.
The only main focus for arsenal to anticipate the comeback by sevilla. This is the only a threat for arsenal but it's quite easy to win the group b.
Arsenal is a strong candidate to win Group B because they are stronger than Sevilla, PSV and Lens. Even Arsenal has players with average quality as quality players, so Arteta must be able to take advantage of this opportunity to bring Arsenal to become group champions in this group phase. Lens and Sevilla are not even in their best form because these two teams are in the bottom zone in their respective leagues. Thus, Arteta was greatly favored by the instability of his opposing team in the group phase. I think Arsenal will not underestimate their opponents because they have to be fully focused to be able to secure full points in every match and Arteta must learn from last season's defeat when Arsenal were beaten by Sporting in the European League last season.