I think people are weirdly, significantly underrating how physical and defensive minded De Jong is.
He's a lot closer to Yaya than Gundogan. Loves a tackle, and he's categorically not slow, I have no idea where that's come from and he's strong, people bounce off him.
Now playing Yaya as a lone 6 was not for the faint hearted and he was at his best with Fern,Nige or Barry next to him, but he could do it in 95% of games. FDJ is the same.
I prefer him as an 8 because under Koeman he really started making late runs into the box and getting goals, and you don't get that when he's got more defensive responsibilities.