There is no way Desharnais is in the lower tier. I think that it is tough for us to discriminate a “top tier player” with another “top tier player” but when we compare a “lower tier player” with a “top tier player”, we can reach an acceptable picture.
For instance, among mid tier players (in terms of speed), I do think that Desharnais is not slower than Eller and Galchenyuk but I won’t fight tooth and nail if you rank Galchenyuk ahead of Desharnais. However, ranking Desharnais in the lower tier, like you did, is plain wrong imo.
EDIT:
I think Markov does look slower this year but it's mainly observable when he needs to make a pivot.
Maybe you misunderstood my post? Of the 7 players in the poll, I have Desharnais as the least slowest of the bunch.