If you want to use Org or vApp networks, you need the NSX infrastructure, because Org networks are provided as VXLANs in the form of logical switches.
In this case, you need at least one NSX manager and one transport zone. Because VXLANs only work within a transport zone. And for the transport zone, you select the replication mode. If you choose unicast or hybrid, you will also need NSX controllers (maximum 3).