Yes, since Trossard was taken off the field Arsenal didn't have much effort in counterattacking and playing the ball more, actually this is an interesting game if Trossard was not taken off, it might be true as you said that it would be an easy victory for Arsenal because they took the lead before the situation was reversed in the last minutes of the second half which ended with a draw, even though I know Arteta is fully focused on playing defense but still they conceded and had to give Man City an equalizer goal.
Basic experience from what I watched in previous matches it's very difficult to survive if Manchester City is ready to attack all out the defense. Arsenal should have continued to attack, not only survive to make the city doesn't focus on attacking. But so far, Arsenal is quite good especially David Raya who has very concentrated to block the ball into the goal. Strategy pretending injured also are unable to maintain their score 1-2 so that situation must be a correction for Arteta to not repeat it again in the next match.