It's going to be difficult to keep the QBs. Both Martell and Perry have already redshirted. If they stay with the team this season and transfer next year, they would have to sit out the 2020 season. They would then have to petition the NCAA to grant an extra year of eligibility. Otherwise they would have only 1 year of eligibility remaining in 2021. If they leave now and enroll at another University this Fall, they would be eligible to play at the new school in 2020. Basically, if either stayed, they'd pretty much be committed to staying thru 2020, graduating and moving on as a grad transfer.
It's really a difficult decision. I think both feel they could win the job should Jarren get injured or falter. The question is whether they're willing to roll the dice.