I don't see any official shutdown sequence in the VCF or NSX docs, but my process for the shutdown has always been:
- Edges
- Non-Primary Managers
- Primary Manager
And startup:
- First NSX-T manager, wait until the startup is fully complete and the GUI is available
- Next 2 Managers
- Edges
From what I've seen breaking this process, NSX-T has been pretty tolerant when violating this order. Edges seem to run "fine" for a while without manager connectivity as long as nothing else changes (DRS manual!) and Quorum seems to function well on the NSX managers even when mismatched startup times are used.
It's a pretty durable platform all things considered, but if you're feeling risk-averse I'd recommend this.