Its hard to imagine how the Bills could have whiffed so badly with their 2nd and 5th picks (7th doesn't count, everyone knew he was a 1 or 2 talent, that was a no-gamble pick—if it works, great, in not, no big deal).
I suspect there is more of an issue of coaching philosophy here than talent (but, a bad coaching philosophy has led to bad talent).
What is the one thing that all Bills line players have in common? Answer: They are all big, huge men.
It seems, we have drafted and signed players who are big first, athletic second. Obviously, if you can get both, you win. But I suspect we are just too slow and un-atheltic to compete against the more nimble, quicker d-linemen of the NFL today. And that won't change with the current crop. I'm sure the hope was we could be a road-grading team, but it is also apparent we are not strong/powerful enough (physics lesson here: power comes from the combination of strength and quickness/athleticism) to do that either.
I really think the Marrone philosophy of "bigger is better" needs to be challenged and changed.