City won 3-0 with pundits suggesting United's midfield was overrun on Sunday.
But Amorim argued: "It’s the same thing, it’s always the same conversation. They (City) put four in the middle, we have three central defenders and two midfielders. You can see Bryan (Mbeumo) is always inside and (Benjamin) Sesko is there, so that conversation is always the same thing. We play last year the same way - of course with difference because the opponent is playing in a different way against Liverpool, against all these teams in the same way.
"So it’s not the midfielders because, again, if you feel that what you are going to do in the first goal has to do with the amount of midfielders. Doku receives the ball, turns to the defence and then takes two guys inside the box. Then the second half, we start really well with two midfielders. You are near the box controlling the game and then throw-in, goal.
"Third goal, you are controlling the game, trying to open the game, Bryan has a great opportunity, Amad is pushing on the side, we had some distraction with going to the ball, Haaland has all the field to run so it’s not to do with the midfielders.
"It’s the way you want to see the games. I saw a lot of teams playing here (at the Etihad Stadium) with five midfielders just blocking and they suffer more than us. I see a lot of games from Manchester United playing here with a lot of midfielders.
"Opportunities sometimes with one, two, so it’s not about that. Again, sometimes we play with the three defenders, five defenders, sometimes it’s five midfielders or two midfielders. It depends on the game of the opponent."