Same logic applies with these denominations.
No, we're not talking about this case since Boltzmann score has absolutely nothing to do with Sybil attacks.
Boltzmann score is useful in case of a malicious coordinator weakening the anonymity set, to the point where only a minority of the inputs and outputs are not registered by the coordinator.
But you don't know that information
You do have this information if you partner with blockchain analysis.
Ta da! By asking your friend to register their coins, you've revealed the coordinator is trying to Sybil attack you
This sentence makes no sense, but even if I need a friend for protection, the anonymity set remains weak, and the protocol is not trustless. I still have to rely on others whom I trust to join coins with me.