I don't have Thompson as a third, but I do have him as a second...
And then, still, I wouldn't really like the pick. He's a guy in the mold of a Chillar, Jones... (not exactly, but you know what i mean) Better than those two, but just as much a LB/S tweener who excells in coverage and underwhelms against the run.
I'd like to see him in the third if he's still around, but he's too specialized a player for my taste in the early rounds.