Arsenal is better this season that they were last season, but it doesn't mean what happened can't happen this season. All that needs to happen for them to fumble the league is to drop point and both Man City and Liverpool drops point. Arsenal still have tough matches to play and those matches can determine a lot. Winning seven games in a row with the kind of pressure teams have towards the end of the season is no easy task.
Arsenal are in much better form than last season, I don't think we should always expect bad resultsfrom them every season, since we don't know if this season will be different. Arsenal has a tough game in their remaining games, if they do not continue to win, they may lose points before the end of the season. Arsenal will play the second leg against Tottenham and Aston Villa, these will not be easy games for Arsenal because Aston Villa and Tottenham need three points in each of their game to qualify for the next Champions League, they had the same points with different goals, I think Arsenal should continue to win their games to avoid the mistake they had last season.
If City was at the top of the season by this point of the season they'll definitely win it. Manchester don't joke around with opportunities like that. The mistake Man City made was not winning Arsenal and Liverpool in the second leg. I doubt Manchester City would drop points again, so they'll be hoping both teams drop points.
Manchester City was at the top of the league this season but they cannot maintain the position. When Manchester City was at the top of the league, they started losing their games, they even dropped back to fourth place due to the absence of Rodri and De Bruyne, but after Rodri returned, they started to win games to moved up to third place. I think we should believe that any club can make mistake like Arsenal.