Does Network routing logic always demand pickup and delivery legs?

In my scenario the network hubs are also DCs, therefore, there are direct inventory transfers between them. That is, Order Release's source and destination are adjacent DCs and it will require only one leg in the network.

In my tests, the network algorithm demands at least 2 legs to be able to plan, it demands a pickup and a delivery leg. Is this understanding right?

Is there a way to setup a network leg which acts as pickup and delivery simultaneously?

If not, I'll have to create ordinary itineraries to manage such scenarios.