Could you explain a bit more how your example of 'a single actor minimizing hops' creates an effective Sybil attack? If I understand, you mean to describe a node which is not adding unnecessary hops but is itself posing as unique identities to different users.
If so, the response to that is: 'this type of behavior doesn't grant this node an increased ability to influence consensus compared to if they routed all data under the same identity.'
If so, the response to that is: 'this type of behavior doesn't grant this node an increased ability to influence consensus compared to if they routed all data under the same identity.'