So Arsenal will Rather fight for a draw than loose because if they draw they will be on four points and still remain second position in the group which will still be considered fair for them and keep them hopeful to make it pass the group stage, this is UCL and only the best is what teams give out and so I'm very sure if arsenal should be giving only but their best then Sevilla doesn't stand a place then because Arsenals best is way beyond Sevilla's best.
Arsenal will qualify first in Group B. Lens won vs Arsenal but they aren't fit to keep winning in my opinion. Their results in Ligue 1 aren't good at all also. PSV Eindhoven is a good team but with lower quality than Arsenal. Sevilla are good too but not that good to end first in my opinion.Arsenal first, Sevilla second for me and if Lens could keep good results, they might pick the second spot.
In Group B, there will be an interesting game between Arsenal and Sevilla, Sevilla fired their coach because of the bad performance they had in La Liga in the past and they surely want to get better results in the Champions League too but Arsenal is the team they won the game against Manchester City and in this season, Arsenal had an amazing performance so far which enough to say they won't have a hard game against Sevilla. The last time they faced each other was the Europe League in which Sevilla won the game and now this is a good chance for Arsenal to take revenge.
