I agree that Arsenal were unlucky to face Sporting. Sporting played very well in the first game and played just as well in the second. But you could say they were lucky to win on penalties. But it can also be said that Arsenal is not as strong a club in the Europa League as everyone has said. Now it's even harder to pick favourites.
I guess that arteta was making very big mistake but did not put odegaard in the main squad since the first half. It's all too late when arteta was substituting him during the additional time. It has been proven that if arsenal's goal keeper is not having skill when it came to the penalty. I just try to comment on how slow the response of arsenal's goal keeper when it was trying to block sporting player's shoot in the penalty.
It seems like that if arteta was also having some bad decision-makers. that's why so many gunners were blaming him caused by he was not even trying to respect his opponent.
Arsenal shall always use the main formation started from the first minute. I don't even understand the way arteta thinks about that. Arteta was underestimating sporting CP. it's not good man.