Yes, it's a shame that last season Arsenal failed to win a trophy and were forced to accept that Manchester City was the champion and this season Manchester City is still Arsenal's enemy and of course it will be a challenge for Arsenal to beat Manchester City this season and they definitely don't want to repeat mistakes like that. last season and certainly Arsenal's failure last season will be a valuable lesson for Arsenal today so they don't repeat mistakes like last season.
Last season, Arsenal shown some dangerous signals from their weak defense system but before their collapse in Premier League started and they lost a first position to Manchester City, they managed to make some impressive come-backs in late of matches. From those come-backs, there were two different views on Arsenal. Some said Arsenal shown that they were strong and it's good for a future champion. Some others said with weak defense like this, Arsenal will soon pay high cost and lose points that is what happened later.
They lost Premier League last season because of their defense system, not because of Manchester City and it is their valuable lesson for this season.
Yes, that is Arsenal's advantage, they have young players, of course the performance of young players will make it difficult for opponents facing Arsenal to beat them.
It is not true to say Arsenal have young players, season by season. Their players grow up with time and after three or four seasons, we can not call them as young players.