The fact that the match would be played at Etihad I think that would give Man City an advantage even without those three injured key players it has always been difficult for Arsenal to defeat Man City right at their stadium I don't think that would change for now the best bet is for Arsenal to draw the match I think that would be a fair result for Arsenal even now that all the players are out for international duties I can't really vouch for both teams to play with full potential, however the odds favors Man City to win based on their past winning records against Arsenal at Etihad stadium but I think Arsenal would give them a run of their money and definitely a tough match is expected between the two title contenders.
The home factor may be a bit beneficial for Manchester City, because after all they will have the full support of the fans to improve their mentality in the game, currently important players for Manchester City in injury conditions and doubt they can appear in the game, but I think the absence of these three players will not make Manchester City weak and even the substitutes of the three players will have motivation To play well in order to continue to gain the trust of Guardiola in the next macths later.
Actually when we focus on seeing Manchester City hit by injuries, shouldn't we also see if Arsenal will now play without Martinelli who continues to be their mainstay all these years, Martinelli's injury has had a big effect on Arsenal's game and it shows when they struggle to beat Brentford and Porto before the international break starts, I personally lean to see Manchester City have the advantage in that game and although it is difficult maybe Manchester City will be able to beat Arsenal at the Etihad Stadium, so it is quite lucky if indeed Arsenal are able to get 1 point in the game if it happens as you said.