I'm not sure Preston is an answer, but he does seem to play more physically than did Fowler. Unfortunately, he also displayed a penchant for some bonehead plays as well.
As for Ellis not been given enough PT to show what he could do, I do recall his limited time on the field, and he got mauled far more often than not. He was frequently knocked to the ground with just a push/punch. Yeah, a bit more weight might be helpful, but he's way too weak to match up with Tackles in the NFL. The "man" needs to hit the weight room in a major way.
I say, plan on him being a wash out. Draft and seek DE's. Kelsay needs to be cut from the team. Denney is solid backup. Schobel may or may not recover his former form (which was good, not elite). If Ellis proves this wrong, fine, we're the better for it, but it's totally on him, his skinny weak frame, and frankly, he didn't look all that quick to me when he was in there laying on his back.