Lokombo is a guy who I thought would take a huge leap forward this year out of the shadow of Kiko Alonso and Michael Clay, but I think he's been outplayed by a couple of our other linebackers Derrick Malone and Tony Washington. He's a good, but not great player who makes WOW plays every once in awhile. I think in the NFL at the very least he'll be a heck of a special teamer because of his athleticism and he'll be a role playing linebacker but I don't know if he'll ever be a star. I'd say probably 3rd round is his ceiling and 5th round his floor. He should do really well at the combine. *fun fact: Lokombo was already a first round pick in the Canadian football league draft (he's Canadian)*
Havili-Heimuli actually got beat out this year and is not starting, but I think that says more about Arik Armstead who beat him out then it does about HH. I'd put our other senior DT Wade Kelikipi right in the same category. They're both capable of getting sacks but its usually after our perimeter players flush the QB into them. They both stuff things pretty well. I would assume they'll both be 5th round or lower type guys. They'll both have careers in the NFL but neither will be a star.
The Ducks best senior d'linemen and the guy who I think will be the best pro is Taylor Hart. 6'6", 287 pound defensive end. He's not a dominant speed pass rusher but was still the Ducks leading sack guy last year I believe. He'll be a really good 3-4 DE in the NFL. I could imagine him doing really well at the REd Bryant position for the Seahawks, and bringing more of a pass rush then Big Red does. NFLdraftscout.com has him listed as a 2nd round guy.
The d'line is definitely the Ducks strength right now. I think they have 6 or 7 guys in their 2-deep who are future NFL players. I wouldn't be surprised if both Armstead and Buckner, who are both true sophomores, will be future first round picks. With Armstead possibly being a top 10 type guy if he continues to develop.
The first guy off the draft board for the Ducks will probably be Ifo EKpre Olumo, the CB. He's almost surely a 1st round pick and would fit right in with the legion of boom, but of course, I really doubt we'll go CB in the 1st round.