He can play anywhere in the centre - is the backup CB/DM/CM/AM/ST.I think that says more about Kante's contribution rather than DD's lack of.
I do think 4-4-2 has its limitations and does leave us very vulnerable in that central area. With 3 in central midfield and a playmaker at the head of that triangle it opens up all sorts of opportunities for the strikers (if they are of the right quality) and wide men.
How/where does Iborre fit in?
Can see him playing as DM more often then not to give Ndidi a rest.