who? breaking sub 4.5??? So you are telling me a lb can keep up with Vick, who has lost at least a step? The difference between a 4.3 and a 4.5 is a nice little distance. I ran a 6.72 60 and was left in the dust of a guy running a 6.58
LB running a sub 4.5 40 is not all that common. A 4.5 is incredible, and I don't doubt there are SOME who can run it every once in a while, but it is no way shape or form the norm. As I said earlier, these are the best of the best of the best of the best. And you mention the combine, which the thing that sticks out about that is obvious, no pads. Pads make a pretty good difference in the speed in which one runs. I remember watching Vick in a game a few yrs back and they times him on ESPN. Something like a 4.25-4.3 in pads, ridiculous. So, no, I haven't seen a lb run a sub 4.5 in pads and frankly don't think any of them can. You say they can, I say they can't, does it really matter in the scheme of things, no.
The majority of the "top lb prospects" out of college are hovering around the 4.5 - 4.6 range. There are maybe 1-2 that come in sub 4.5. Safe to say sub 4.5 from a lb is not the norm. 4.5 is still fast, don't get me wrong. I would say that the majority of guys under 4.5 are d-backs and rb's. Beyond that, I think the speed is average (for nfl terms, fast for everday individuals)
There aren't a lot of failed drug tests bc it would hurt the revenue fromthe NFL, simple as that