Assume for a moment, either by severing the interconnect cables or by a mobo/nvram issue that fries c0a and c0b on one head, that `storage failover show` says SFO is dead on your 2-node cluster. (don't say it can't/shouldn't/won't happen. Really. Don't.)
The docs say, for a 2-node, "both nodes are continuously polled to ensure that if takeover occurs, the node that is still up and running has full read-write access to data as well as access to logical interfaces and management functions." But if there's no interconnect, then what?
If you don't have SFO, but do have space, you can vol move over and reboot the damaged head. But without interconnects, when that damaged head goes away and the clustered interfaces stop responding, haven't you just gone split-brain?
For that matter, what DOES an OOQ NAS cluster look like if you go poking around ngsh while it's OOQ?