I have a hard time wrapping my head around what you are proposing here.
Say client A requests data, they get the token a-abc. Then client B requests data, they get the token b-cde. Client A commits their write, does the storage reject it because they already issued another token (the one from client B) or does it accept it?
My understanding of what the OP was discussing is an optimistic locking system where the nodes only accept commits if the last issued token matches the token included in the commit. While agreeing on the last token requested requires coordination, unlike monotonically increasing tokens you could have well-behaved clients generate token content themselves without coordination. That may or may not be useful as a property.
