ya, screw that Eichel kid
I'd much rather have Mittelstadt with ROR and Reinhart, and put a vet like Girgensons (or Boedker or Hagelin or Sheary) with Eichel if Nylander is Eichel's RW, which is what the prior post proposed.
If you have Okposo as Eichel's RW, then I think there is room for Mittelstadt on the left.
No way would I place 2 rookies who have never played together as Eichel's wings on Day 1, unless we want to see Jack play a lot of 1-on-4 and 1-on-5 on offensive breakouts, and a lot of odd-man rushes coming back the other way.