Premier league this season will be different from the one of last season, last season it was Arsenal and Manchester City that was fighting to get the championship but this season more teams are joining the race of getting the championship of premier league. Other teams are really getting prepared to come out with good performance for next season, it might not be really easy for arsenal to continue to fight to win champions league because their are other teams that will also be challenging to them. The next season is just too unpredictable for arsenal if they will go far or not in the premier league competition.
As the season has not yet started, I don't believe it is appropriate for you to state that it will be difficult for Arsenal to compete for the title because, even prior to the start of the previous campaign, no one anticipated that Arsenal would perform to the point where they would finish second on the Premier League table. However, once the season got underway, we saw that their performance had significantly improved, and those teams were anticipated to perform well and compete for the Premier League title their not that in form.
I don't believe anyone will suggest Arsenal won't perform well and compete for trophies next season if we assess them by their current squad. The only thing I can guarantee, though, is that it won't be so simple to forecast what will happen in the upcoming season as many teams will be bolstering their rosters. I won't even be astonished if I learn that clubs like Newcastle or Aston Villa are vying for the Premier League championship once the season gets started.