Group B is an easy one for Arsenal. They can even win all of their matches if they concentrate on all of them equally. They might be a young team now but they are still way more powerful than all of their opponents in this group. The only competition might be made by PSV against them but I think Arsenal wouldn't struggle against them too much either.
This feels like no different than a Europa League group honestly. I remember Arsenal and PSV in the same group there before.
When it comes to Sevilla's chance in this group I think they will finish behind PSV if they don't improve their current performance.
Arsenal got a good spot I must concur and PSV has always been a worthy competition in getting the team the three points they need. For the preliminary stages, I ain't scared until it gets to when the pressure of premier league and other league matches starts bumping weekend in, weekend out.
What the gunners need is a team that doesn't lack stamina or whose muscles bow to cramps once the game gets above 90minutes.