Agree.
Lacks desperate defensive intent when they have advantage in the contest, and then possession.
Sometimes it's just a lunge here, or an arm or hand in there, or even sprinting to the contest rather than jogging.
Not sure its teachable, more like the instincts a natural footballer would have.
And super important if inside contested work is your bread and butter.
I'm pleased that after three years on the list RCD is finally getting decent continuity at senior level.
But, like Jack Ross, I have a nagging suspicion his upside is capped at Average Player.
Too early to be definative. And really hope I'm wrong.