Your observations are perfectly correct because Tuchel really made lots of mistakes in that world cup outing and one of the biggest I know was not including Cole Palmer to the squad. Tuchel justified such decisions with Palmer's decline in performance, fitness issue and others. Despite this, I still believe it was a mistake not adding him to team because his presence alone would have made significant impact in the team and whoever is playing them will be careful seeing Harry Kane and Cole Palmer in the front.
It was not just palmer exclusion that was a very big mistake, the exclusion of Folden and Alexander Arnold was a very big mistake, because in most of their games they played in the world cup, they always struggle to break down teams that seat deep and plays on the counter attacks, so they need creative players like them to do the magic in games like that.
Against the Argentine, the only mistake tuchel made, which was the biggest of them all is to go defensive against a team that have someone like Lionel Messi very early in the second half. I knew that they would not be able to hold on to their lead especially when Pickford was making a lot of saves. So I knew that it's just a matter of time before the goals will start coming, and I was not wrong at all.