If all devices have the same shared secret, and share a (management subnet) IP space, you can create a Network Device configuration for the full subnet (10.1.0.0/16 for example as IP).
If you can't summarize, have unique shared secrets, or other reasons you prefer to have a per device Networks Device configuration in ClearPass, you could use the ClearPass NAS Batch Import solution on Aruba Solution Exchange.
Is this an answer to your question, or did I misunderstand?