Arsenal may not facing Barca and Munchen in Group stage, but they still will face PSG. PSG Still strong without Ibrahimovic. And it still hard to beat them.
PSG is strong sure but last game they mess up lost but this is happening cuz they still raising form and team is not fully set up i believe they will manage this season fine
PSG might be still the strongest team on Ligue 1 even without ibrahimovic but in European Competition (Champions League), I doubt they can do something better than what they did last year.
Lucky them that they are in a easy group, maybe they can pass the group stage on 2nd position under Arsenal.