Well right now there is no disagreeing the fact that Martinez has been absolutely brilliant for Manchester United, i think he has to be their best signing of this past summer transfer window, he has completely cemented his place in the heart of United's defence and also in the hearts of their fans as he is fast becoming a fan favorite.
Having said that, he isn't the only one on the top of his game, Dalot, Eriksen, Rashford, Casemiro and a few other players are absolutely firing for Manchester United, it is safe to say that Erik Ten Hag has improved the squad, they just need to continue in this same way and see how high in the table they'll finish, i think they'll get into the top four, then they could prolly win one of the domestic cups, either the FA cup or Carabao cup, if it happens that way, then we might call Erik's first season a success.
Yes, I see Ten Hag able to make a positive change for the game from Manchester United. Apart from some of the players mentioned who can perform well, the way they hold the ball and create attacks is also organised. They are very calm when holding the ball in defense despite the pressure from the opponent, although there are still minor mistakes, but that they can improve game by game. In attack they build up more from the back and all the players are involved in their attack, which they didn't do last season.