I don't think if that's right to compare Arsenal and Juventus and say if Sporting will have a harder game against Juventus than Arsenal or not. It is not the same story for Juventus I think Juventus will try to avoid making the same mistakes as Arsenal in order to avoid giving Sporting a chance to win the game because both teams will use different systems. Arsenal lost the game because Sporting knew their weaknesses and how to overcome them. While Juventus will try not to do the same mistake as Arsenal in order to give Sporting a chance to win the game.
Juventus will look forward to playing defensively, Alegre often does this, and Arsenal tried to solve everything in attack. I'm not sure if Juventus are stronger than Arsenal, rather the opposite, but you're right that the teams will have different strategies and that will determine the outcome. It is very difficult for me to determine a favorite for myself in this confrontation, the teams have equal chances, probably Juventus is more sympathetic to me, but this in no way means that they are stronger than Sporting.
Another thing we need to understand between arsenal and Juventus, this two teams are different when it comes strength of performance and targets, sometimes what makes a team to win a game is the target and focus. Arsenal has the strength of beating Sporting CP but they were not really focused because they have another target.
Juventus may not have up to the strength of Arsenal but because of their target and focus of winning the game can make them to defeat sporting. But the game still remains unpredictable, but Arsenal lose to Sporting will still be the same outcome for Juventus, Juventus can achieve it if winning the europa league is their target.