when they say undersized in David's case it has to do with his weight, Zach Thomas was undersized because of his height (5' 10" IIRC), Thomas was more of a Sam Mills type "undersized" LB, either way, I think he could become a really good pro, he's the best LB I've seen play against us this season, these draft guys get too caught up with the "prototypical" size at positions, if a guy can play, he can play...period, there are a ton of undersized players in the NFL at their positions, we had two guys that were about Lavonte's size play in the NFL (one played safety [Cato June] and the other played LB [ian Gold] at Michigan)...
that said, the kid from BC is probably gonna clean up on the LB awards, he can ball too...