Tottenham has been terrible all season long, in fact they are worse than United, and not many people talk about why Tottenham is bad, or how they are bad, so Arsenal of course had an easy game. I know that Tottenham has a big name, so that is why everyone was worried about the game, but they only have a big name this season, they have no talent at all, no success, they are 14th.
Last season began very well for Tottenham and in some weeks, they even thought of competing and winning Premier League title. The last season did not end too good for them, and this season is like a continuation of this. They are playing not too good, and nearly bad in this season with their potentiality. Two seasons after Harry Kane left their club, their quality and competitiveness continue to fall down and only Son Heung Min is not enough to help their club generally. This player individually plays worse than previous seasons too, and it's part of reasons for Tottenham Hotspur's bad performances so far.
Of course United winning this week put Tottenham lower, so that's a part of it, and United looks much better with Amorim, they literally knocked Arsenall off FA cup, making sure that Arsenal wins nothing this season once again, so beating Southampton after that was piece of cake for them. League is getting more fun, we are finally seeing teams be more established and showing more.
Winning a match is good and Tottenham by many means, are not too weak team in Premier League. They have been performing worse than expectation in this season, but it's wrong to consider them as a too weak team. They can beat any big club in Premier League in their good day so a win againt Tottenham Hotspur has its high value.