This all sounds quite sane, but in the end depends on your goal.
Local snapshots give you protection against logical errors or operator faults. If all VMs vistual disks are located on the same volume, volume snapshot gives you crash consistent backup. For “not so important” VMs it could be enough. To have more confidence in recoverability you could use something like SMVI to ensure data consistency before snapshots are created.
If you need protection against physical data loss, you will need to create secondary data copy on tape or another storage. In case of NetApp the obvious method is to utilize SnapVault, which is D2D backup tool for NetApp environment.
Incidentally Commvault have very good support for NetApp, including snapshots of virtual clients and SnapVault, D2D(2T) and is perfectly capable of doing everything you described. What is your goal? Do you intend to free some CV licenses?