Arsenal has performed very well in the last few matches. Even though they had difficulties against Porto, in the end they were the ones who qualified for the next round. Arsenal is the most aggressive team in the PL this season. They have scored 70 goals. Arsenal is very strong in the English league and this will be a big challenge for City. The bookie favors City but I bet the match will end in a draw. Both teams are in contention for the championship title. So I think both teams will try to play carefully and minimize mistakes. I really can't wait to watch that game.
Bookies who favor Manchester City also have their own reasons apart from seeing that the match will be held at Manchester City's home ground. However, what you say is also true that Manchester City must play more carefully because the opponent for next weekend's match is quite a serious opponent for him if you remember about the fight for the title this season. Because Arsenal will also use all their abilities to win at home to Manchester City or at least not lose the match even though the position of the two teams could also suffer a slight loss if Liverpool can win against Brighton at Anfield.