Arsenal cannot boost of 100% sure of winning the game against Manchester United despite they are at home, the both teams are in good form and may likely tie points on that game. But if Arsenal win the match they will become more comfortable on the tables top, then on the other hand, if Manchester United won, they will be encouraged more to contest for the league.
If that was the case, I'm sure Arsenal can beat Man United. But right now, I still can't guess because I see how Man United's performance has recently developed very well. Especially after they beat Man City, their confidence and motivation certainly increased. That is why for now, the match will be more unpredictable and interesting to wait.
Even Manchester City can't keep up with them interestingly. They have had serious issues in not only some big games but also against smaller teams. I won't be surprised if the gap with Arsenal gets bigger in time.
Even though they have a mainstay player who is currently in the spotlight, Haaland. But in reality, football is about 1 team. Man City does have many talented players. But on the other hand, somehow they failed to win several times so they had to lose points or just draw. Currently, Guardiola is being tested to find solutions and create tactics that are very suitable and triumphant for his team.