Manchester City are an important team and they have strengthened their defence by reinforcing Gvardiol. Still, I think Arsenal is a team that can compete with them. Both teams had competitive matches last year. Even though Arsenal haven't been successful in their last period, I can say that Manchester City is the most difficult opponent. I think we can see a rivalry between the two teams this year as well.
Some saw his decision to bench De Bruyne as a gamble against Arsenal possession based style of play, while others like yourself acknowledge Arsenal improvement but are still hesitant to compare them to City. Guardiola frequently bases his judgements on his strategic understanding and this early season action may have underlying causes. Although the prolonged extra time did draw criticism a more comprehensive analysis indicates that Arsenal may not yet be on the same level as City in the Premier League race. If these advancements can actually overthrow the current dominance only time will tell.
If we are to be fair in our judgement about Arsenal, we will have to admit that Arsenal has been good since last season. And their Cup final with Manchester City few days ago proved that Arsenal is a club to be feared this season.
I see that some people are always not comfortable comparing Arsenal to Manchester City. Thy feel that Manchester City is in a higher level than Arsenal. But I can tell you that the difference between Manchester City and Arsenal is just the squad depth. If Arsenal has a very good bench just like Manchester City does, Manchester City cannot beat Arsenal in England.