Can't... too many layers / barriers. Remember, the Patriots HC is also the GM. I'll bet Ther Pats GM had Van Noy high on his list, and saw an opportunity to get him on the bargain rack. In addition, the coach/GM knows his strengths and versatility and just where/how he'll fit in. Wait and see a few games down the road when he has a sack or two, some pressures, and a great play/pass breakup or two.
For us? Pagano walking down the hallway... "Ryan, a staffer tells me Van Noy is available. Can you get him?"
"Chuck, heck no. We are not giving up draft picks and our future up to get some flailing players on others rosters." Walks on by...
But he beat the Colts ;) Wentz and Dak are exceptions. Rookie QBs usually don't play to the huge level that they have so far. I haven't watched either of them play either so I can't say anything about their rookie mistakes.