Fair enough, mate. Here's some counterpoints for you to consider, though -
1) Hugo is not making errors because he has stopped taking any risks whatsoever. He used to be a sweeper keeper - he's now a granite statue stuck to his line, an above averave shot stopper but a poor overall keeper in comparison to the best in the league.
2) Aurier was an atrocious, braindead headless chicken of a footballer, and he isn't now. But how much of that is him, and how much is a system which absolutely babysits him by having *three* players tidying up after him ? (Winks, Sissoko, Sanchez).
3) I know people think Dier's improved, but I'm still doubtful, because, like today, he still fudges up pretty frequently. I think he, and Aurier, and Lloris, have benefited from a system which puts four five defenders ahead of them and then has them do a minimum of thinking - sit deep, clear the ball, repeat. But if we were to play an expansive game, how many of the old flaws would return? I'm guessing a lot.
Improving players, to my mind, means helping them cut out errors and develop their skills, not covering up for their omnipresent weaknesses by building a risk-free defensive system that surrenders the ball to every opponent thst comes knocking, even Fulham.