Ok, I think I can articulate a reason for my doubt about the Shapley Value. One nice property for a fair division method to have is that the players can't game the system by transferring their underlying contributions to one another. That is, Alice and Eve shouldn't be able to increase their total negentropy allocation (at Bob's expense) by transferring matter from one to the other ahead of time. Proportional allocation satisfies this property, but Shapley Value doesn't (unless it happens to coincide with proportional allocation).