Having better squad depth than Sevilla will not guarantee that Arsenal will be able to beat Sevilla easily. Sevilla playing at home will certainly get direct support from their fan base and that will raise their enthusiasm to perform better to win points. Sevilla have not won a single match in the two matches they have played, so this will also be considered an opportunity.
Sevilla was a strong team in Europe even though they mostly failed to progress far into the next phase. I believe Sevilla will strengthen its defense and develop the most deadly counter-attack strategy to beat Arsenal. Of course Arsenal are favorites because of their performance, but however Sevilla is a team that can do something in their favor.
In the Champions League, every match will be difficult to predict because, like when Arsenal were beaten by Lens, of course the result was beyond many people's expectations. So the team's strength is not a strong enough benchmark to guarantee they will win the match. Moreover, each team will play quite well in the Champions League, where their game will be difficult to predict. But seeing that Arsenal lost in the previous match, of course arsenal will improve their performance better when they face Sevilla.
We will see Diego Alonso handle sevilla in his first match in the Champions League after he was appointed as sevilla coach. He has no experience in the Champions League but still Sevilla will fight well to give their new coach a win.