I was just about to say the same thing. Quick is not always better. As seen with Verm and Toure, they dive in too quickly for tackles and can be too aggressive to win the ball back. They’re recover pace compensates reckless positioning and decision making. Merts isn’t a bad defender. What he lacks in pace, he makes up for with positional play and decision making. We need him in our back line. He’s slow but he helps organise the rest.