RPC ordering details

Maybe I'm misunderstanding something, but I've been having troubles with understanding how RPC ordering can be "guaranteed", unless that guarantee is only that RPCs will be executed in the order they were received, not sent. For example, if two clients simultaneously send RPCs to each other, but local clients run RPCs immediately, then each client will run the RPC they sent first.

Unless the Unity docs mean to say that RPCs the local client sends will always be executed in that order if you exclude all other RPCs. But not all clients will execute all RPCs in a unified global order, and RPCs from various clients may be interleaved in different ways. Is that correct?