I think PSG will dominate from start to finish. Honestly, I don't see Arsenal playing with their full potential, as they sometimes show. Right now, they have all the pressure of winning the Premier League; one mistake and they won't win. They're on the verge of being inconsistent. I think this stress is what has made Arsenal neither here nor there, but rather they just stay put as if they don't know what to do. They could win everything, just as they could lose everything or end up with only one championship.
Arsenal are weaker and they are favorite with playing defensive and counter attacking so facing a very strong PSG, there is no reason to convince and force Arsenal playing attacking proactively. I agree with your prediction on Arsenal possible tactical approach for the final match, they will play with what they are familiar with, even master it well, defensive and counter attacking. It's how Arsenal can tighten their whole system with plan of constraining very strong attacking power from PSG but it's just their plan. PSG are simply too strong and flexible with many attacking solutions from their team movements, transitions to world class moments of their star players.
Hence, playing against such PSG is never easy for any club in Europe now, not only Arsenal, but with only one final match to play, with a result of either winning a title or losing it to PSG, Arsenal players will use everything they have, even more than that for winning the final and lifting a trophy. Even many legendary players never won Champions League title like Ronaldo Brazil, Buffon, Totti for example, so all Arsenal players are aware of the very great opportunity they have now.
