With the current performance of Manchester United this season in the Premier League, Manchester United can't beat Arsenal at Old Trafford. Arsenal will not want to drop another point in the Premier League because it will affect them in the race for this season's Premier League title. Arsenal has already made the same mistake they made last season that cost them the Premier League when Aston Villa defeated them at Emirate Stadium.
I want to be believe you as well, I want to believe that Arsenal can take down Manchester united without putting much effort but I don't think the United I know will allow this guys to go for free, it's when you least expect something good from them you will see the soar high. I hope they don't destroy the winning steak Arsenal are bringing after their numerous losses against Bayern and Aston Villa, a lost from moment from now is going to stop Arsenal from becoming the Champions.
Manchester City are still serious but my mind if telling me hat Tottenham is going to be there nightmare, no way they are going to allow Manchester City to go scot free, they have win some matches against them. If the can just lose this one, then the assurance of Arsenal has just been double, they can actually win this league even by a small margin of points.