Don't want a repeat of the Demarcus Ware situation, he was a great outside linebacker who rushed the passer a lot, then he was put at mainly defensive end and he began to get hurt and his production dropped off. Parsons said he was trying to bulk up, but unless he has added or can add another 20 pounds or more, he'll still have trouble handling 300+ pound OTs if he's at DE most of the time, and keeping that weight on during a long season is very difficult.
Putting him at DE most of the time is fine, but his effectiveness is enhanced if he is moved around so the offense doesn't know where he's coming from on every play.
Just my 3 cents worth (inflation, ya know)...