You have the worst kind of confirmation bias I have seen in a long time. You pick a single match and deduce that it means top teams can be won by the teams outside the top six. And you also decide to basically brush away Koeman's wins against the top six. You also completely disregard the fact Arsenal have been quite shite for some time, but yet beating them is somehow a better accomplishment than beating City.
Yesterday we lined up with three forwards, yet Koeman wasn't trying to win?