Arsenal 2018-19 Season. Fail?

As we all know, last season, Arsenal has struggled a lot. Losing to a Newley promoted squad (Brighton), losing star Alexis Sanchez, losing star Olivier Giroud and much more. Arsenal this season has been now under new management. Unai Emery has taken charge of Arsenal after PSG replacing Arsene Wenger. In the pre season tournament, Arsenal have done quite well. They have beat big teams.  Then in the first 2 matches of the Premier League, they have lost. First, the lost to Manchester City 2-0. Then on their second game, they have lost to Chelsea 3-2. Now in a London Derby, they face West Ham United which has been spectacular in pre season, but bad in league. But I have a hint that arsenal can struggle against West Ham or West Ham could struggle against Arsenal. What do you think? Will Arsenal struggle again this season like last season? or will they be Successful? what do you think?