Incorrect according to you. But I think Ellis can actually clog the lane pretty well. Granted, Spears is somewhat of a lane clogger or defensive tackle type. But he's a tub but and lacks mobility that is necessary. Even for a 3-4 type linebacker, Spears is slow and somewhat ineffective at times if you pay attention closely.
Now Canty I think has the athleticism of Ellis, but he's kind of an upright player and really hasn't shined at all at the 3-4 DE position. In fact, I think that he's been a disappointment - same goes for Spears.
And while Canty may be athletic, I don't see much that Canty can do that Ellis doesn't. Ellis definitely has the stats to back up the notion that he could probably play any position on the defensive front.
Saying that I'm highly incorrect is nonsense, particularly since all of this is merely conjecture. And Ellis has handled quite a few offensive linemen. His experience gives him the edge.
Don't forget this post when you see him line up at multiple positions, including defensive end, if he does indeed return healthy.