Is his miche white, whole wheat, or both?
Poilane had his flour milled to a high ash content; it equates to around 93% extraction on the US/UK milling system. That said, French flour is quite different to that found in the US.
That makes since, but do you know if it is a white or wheat bread? Sorry, that's a hard question! I've tried BBA Poilane styled miche, but it wasn't quite what I expected. Peter's is more of a heavy whole wheat (39 whopping grams of it!).
According to a recent article by James MacGuire, Poilane uses stone ground French type 80 flour which contains significant amounts of the wheat germ and aleurone. Practically Edible has more details on the flour.
Mixing white and whole wheat North American flours will not give the same results.
Lindy will be right be a T80 flour. But the answer to your question is that the bread is a 93% Wholewheat Bread