Correct me if I`m wrong:
You have primary disk-based backup repository, secondary disk repository and a tape repository.
You need to have 1 year-long retention for backups on the secondary and tape repositories.
You are going to schedule backup job for the primary, backup copy job for the secondary and backup to tape job for the tape repository.
If I`m correct, it can work great, you just need to set a proper retention policy for those jobs.
Backup job can be forever incremental and have as many restore points as you need on the primary repository, backup copy job may use GFS retention policy
to achieve flexible historical backup hierarchy. And for to-tape job, you can also schedule backup frequency and retention for the tape media.