v10 did not make use of policies, IIRC, but you can create Batch/CMD files using BEMCMD, and call them from preceeding jobs aas POST jobs
or if you don't care about the "execution time", you can schedule the second job for 15 minutes before you expect the first to finish, pointed at the same drive. it will hang in "pending" status until the drive frees up, but the job timer will be running the whole time