Arsenal are not going to win the league and neither are we so I won't go down that route but what they are doing is beating who they should like you say and doing it handsomely, something they have not always done and as you say something not all top 4 contenders will do, or have already.
They key for me has always been how you beat those you should because those are the easier points to haul and then it takes heat of when you play your rivals, the years under Poch at our peak thats what we did really well, 2/3 nils up at half time against teams we should beat, but we beat them well.
Arsenal are a much better side than last year, I can put rivalry aside to admit that, Jesus looks a player for them and I was wrong in my early assessment of him, they also look very good in other areas, that Viera looks handy as does Saliba.
Top 4 looks a real possibility for them