McNeil is already 27 so he's significantly over-aged for a traditional developmental-type prospect, never mind one who just transitioned to an entirely new position last month. Better to make the initial investment in younger guys like Coleman and Short whom you want to get a feel for, knowing that McNeil can (and likely will) float in and out of the PS over the course of the season as needs dictate.
Also, Robert Thomas was incorrectly labeled a DE. He is in fact a Mebane-type 1-Technique NT who measured 6-1, 327 at this Pro Day, with 33 7/8 inch arms and 10 inch hands. He was coached in his senior season at Arkansas by then new-HC Bret Blelema, whom John Schneider is close with from Bielema's time as the HC at Wisconsin.