LB is much like RB in the sense that 80% of the playing the position is INSTINCTUAL.
It's nowhere near as technical as D-line or DB. You guys are over-emphasizing the whole "development" thing.
In a perfect world your DL coach would recruit/develop a kick-a$$ D-line that would allow your LB's to use their instincts, run free and tackle everything that moves.
The guy with the best nose for the football plays LB, and that's not something you can teach. You also can't teach speed, intensity, a dog mentality and "want to". You RECRUIT those traits.
You can develop little nuances and techniques like striking/defeating blocks, pass drops, tackling, etc...but you can't even get to the point of USING THOSE THINGS unless the kid is going in the right direction first.