I'm not an Arsenal fan, but I disagree with you that Arsenal lacks a winning mentality because if it were true that Arsenal lacks a winning mentality, they couldn't have finished 2nd in the Premier League table for 3 consecutive seasons. In my opinion, I believe the lack of a quality striker was the reason why Arsenal failed to win the Premier League title when they were close to winning it on 3 occasions. Since Arsenal has signed Gyokeres, I am seeing them to win the Premier League title next season unless Gyokeres fails to replicate what he did at Sporting CP at Arsenal next season, before Arsenal misses out on the Premier League title again.
I would've love it when you have another expression of what arsenal lacks mates, do you know how last arsenal smell the English premier league title, it has always been near to success syndrome, since you assume the reason why they have been unable to win the English premier league title it is fine, atleast they now have Gyokeres in their team, it means they have gotten what they have been looking for right, them we were waiting to see how they are going to win the English premier league title this coming season, mate sporting CP is not the same with English premier league, both of know how highly competitive the English premier league is so if Gyokeres isn't able to pay exactly they way he did in sporting CP we shouldn't blame him that much.