I think we go DT because Hatcher is the perfect 5-tech for this defense at LDE.
OTOH, at DT Ratliff is coming off of an injury. Crawford is more of a 3-tech than a 1-tech. Lissemore is more of a rotational player. We don't know what is going to happen with Brent.
Now combine that with this draft being full of high-quality DTs and I think it is a natural position for us to invest a high pick to get an impact player. If the high impact guys are gone (Floyd and Richardson) it may make most sense to trade down into the late first or early second round and go after one of the guys in the second tier (Short, Jenkins, Hankins, Williams...). Hopefully with that extra pick we'll be able to grab a Safety and an OG in the second round.