That is not true, Man City was defeated by Arsenal just once and it was 10 days ago which is still their first and only match together this season. Maybe you mistook it for the Community Shield game, this happened before the EPL started and can't be counted as part of this season. Everyone has their opinion though, and for me, I will choose Man City over Arsenal multiple times over. My reasons are simple, the team is better and more consistent, only they are not focused for now, this happened last season and they overcame it, the absence of Kevin De Bruyne is another issue right now. This is not peculiar to Man City, clubs do have those moments, the Arsenal time is coming as well when their morale will just drop. I wonder what Man City will do to them to avenge the mere 1-0 win that time.
But with Chelsea, Newcastle and Brighton narration, I agree 100%, Chelsea is not that club anymore, this is in spite of the huge amount spent in the last and this season. A very lesser club could beat them, so I won't blink to pick Arsenal over them on Saturday.
When Manchester City was defeated by Arsenal, I didn't think that Arsenal was stronger than City, even though we all know how that 1 goal happened, it was like luck hitting a City player and ending in a goal.
I'm pretty sure revenge will be taken if City still has a scheduled match against Arsenal again. Manchester City will respond with more than 1 goal.
But if we talk about Chelsea's match against Arsenal, it is certain that Arsenal will win because the depth of players between these two clubs is very different and the players are superior to Arsenal, so even though they are playing away, Arsenal will be favored by the bookies with very high odds @2.31 is very good.