You are correct, you have to do at least one to generate it.
I would also recommend only using an inifile.xml if they are the same release of the SMD, for example don't use a 711 SMD xml file for a 730 installation.
Or if you change to a new SolMan system and change passwords/hostname/instance number that would also impact your xml.
However for hostname/instance number I would just run through the xml and do a 'ctrl h' and replace all of the old info with the new info (same process as a stack.xml file for upgrades) and save myself from doing a new SMD install just to get the newer inifile to generate.