So you're assuming Colvin, at 250, will come into to play backup DE? I couldn't disagree more. First of all you are asking him to play a position he's never played. If he comes, he will most certainly play Linebacker. You can wish he played DE like an edge rushing LB all day long, doesn't mean its gonna happen. I cannot emphasize enough that he hasn't played in the 4-3 in six years, and even then he played LB. He didn't play DE in college or the pros. Please show me the press clipping, web page, quote box, or whatever that says Colvin is coming here to be a backup DE. They want him to come in and add that pass rushing ability from the LB spot - just like he did with the Pats and the Bears.
I don't doubt that he still has skills, but he failed NE's physical and was released. He's been courted for near two months by the Colts but still hasn't settled on a deal. If all he wanted was to play for a contender, he'd be back home in Indy. He wants a payday. That's why he's shopping himself. Look - he's coming off a foot injury that shelved him for the second half of last season. You think he still has that speed he had when he was in his heyday? Naw bro. He's had both a hip injury and a foot injury that caused him to miss significant time in his career. He's damaged goods. I don't want to see the Texans take that kind of risk on a 31 year old player - not for the money he's looking for. He was due over 5 mil from the Pats, I'm pretty sure he would like to see something in that ball park.
As far as the LBs with speed - All three that I mentioned have that in spades. All three are athletic enough to rush the passer if given the opportunity. All they need is their number to be called. They won't get that experience playing behind Colvin. I'd rather take my chances and mold a young player, rather than take an old dog and try to teach him a whole bag of new tricks.