Please read following solutions regarding combining the Autodesk licenses files.
What if a feature is repeated twice in the license file and the licenses are issued the same day?
If two licenses contain an identical feature code of the previous versions, the order of the feature within the license file, determines which license is issued first.
o I.e.: PrDS-Premium 2012 and PrDS-Ultimate 2012 both contain the AcadM 2010 feature code. In the license file, when you combine the licenses make sure Premium is on top so that starting AcadM 2010 it will take the Premium license first.