Re : ID and databasechangelog - LB does not check if the order changes

The full 'unique identifier' of a changeset is the changeset author, id, and file. In your example you have two different authors, so Liquibase considers them as two different changesets, and will try to apply each of them to any database that hasn't had them applied previously. 

Steve Donie
Principal Software Engineer
Datical, Inc. http://www.datical.com/