No, Arsenal last season was started quite good and they achieved many points, the mistake was happen in the near end of the season and Manchester City able to overtake Arsenal's position. Arsenal was only sign few players and most of their players are veteran, so there was no big change and they will with the same strategy.
While Chelsea, pretty much like a new club who has new coach and new players.
Arsenal I started very well in last season, they were ahead of Manchester City with good number of points. What affected Arsenal from ot winning their games towards the end of the season was because their players had exhausted their energy, and this was the only set of players they had in the team, if their were sufficient players in the club it would have been difficult for them to start performing bad later in the season. Arsenal really did very well in their performance last season, I'm sure they are ready learn from their mistakes of last season .