Well, like you said, Arsenal's opponent is more weak, and for that Arsenal have a more chance of winning that encounter than their current competitor which Aston villa, though Aston villa do stand a good chance of beating Newcastle, but the fact remains that Newcastle united is not a club to be underestimated.
But all the same, I am expecting Arsenal to score more goals in their encounter with Nottingham forest, but this is if they don't end up disappointing us, because personally, I've come to believe and see Arsenal as one of the most inconsistent club in the premier league, they could disappoint when one least expect it, so, I am not gonna be all in on them beating Nottingham, but if they will, then they do stand a chance of scoring more goals than Aston villa has with Newcastle united.
For me any time any day, I will still choose Newcastle United over clubs any club for a straight winning unless I am confronted with such choice and clubs like Asernal in involved, but if it smaller clubs like Amston villa because it becomes easy for Newcastle to win but if they are up against clubs like Asernal who is a world champion and also a top club in the premier leagues, it will become impossible for them to record such success on the long run, but also as we have seen in a number of matches, it is very hard for us to predict which club will win or fail in this regards because even the smallest club, could put up the most unexpected performance and going after to win the match, regardless of the class or statues of the club, becauseost times, football is an unpredictable games.