Who would you take at #9 in this scenario

If the team is really moving to a 3-4 either Young or Granderson are going to have to move inside to DE or one of them will have to moved/traded. It may be the temporary solution as the team makes the transition from 4-3 personnel to 3-4 personnel but it will not be the long term answer.
Young and Granderson are projected to be the starting OLBs in the 3-4. They aren’t ideal to be full time 3-4 DEs since they aren’t heavy enough to constantly take on doubles every play. They’ll get some 3-4 run with their hand in the dirt. But their skills and experience are best suited as standup rushers in 3-4.

Grando could be traded because a new definite starting OLB/edge rusher was drafted high, rather than position alignment. But a trade feels more like what we want to see happen than what’s realistic. The starters at OLB are in place.