Nah, with all due respect you're just wrong. I'd argue that Napoli were better than Bayer and Marseille are better than Sociedad. The latter pairing being pretty similar at worst. The idea you'd rather play Napoli than Sociedad is just ludicrous. Then obviously Dortmund are probably the best side out of either group.
Marseille aren't close to being on the same level as Shakhtar, let alone Sociedad. There are even far better French teams around compared to Marseille who were incredibly lucky to stumble their way to 2nd last year, and have been very average this year. Sociedad on the other hand deservedly came 4th last year in a league far tougher league. The Spanish league's lack of depth is sometimes cited with some justification, but it's still far stronger than the French league; Sociedad beat Lyon 4-0 on aggregate just this season for starters.
As I said the press seem to have decided Sociedad are not very good for no apparent reason; they've lost a fair few games this year but mostly to teams that would beat most sides in Europe. They've lost to Barcelona, Atletico Madrid, United, Shakhtar and Rayo Vallecano. Only the last of those isn't a very good side although admittedly they probably shouldn't be losing to Shakhtar at home either. The rest are all games they can scarcely be criticised for losing and they've otherwise looked pretty impressive this season IMO.
Leverkusen have looked just as impressive as Napoli have this year in a far better league, so I think them being better than Napoli is honestly not that close. Shakhtar are incredibly underrated by a press that I assume rarely watches them play, because anyone that has watched them play in the past five or so years would have realised they were a very good side. Until they sold a couple of their key players I'd honestly have had them as a top ten side in Europe. Obviously not as good now but still a very decent side.
If Arsenal were even as short as evens when they go away to Napoli then I would gladly snap it up, barring an extreme change in form for one or both of the sides between now and then. I doubt it would be necessary though as I imagine they will be quite a lot longer.
EDIT: To give some kind of reference, I think Leverkusen are just as good as United and our 4-2 victory over them was Moyes' best moment so far. I also think Sociedad aren't far off as good as us and due to home advantage I made them favourites before the game kicked off last night. When the group was drawn I thought there was a serious chance of us going out and there still is a bit of a chance obviously.
