Controlling order of subsystems using Simulink Reports

Has anyone had success controlling the order of subsystem descriptions when generating a system description document using Simulink's reports feature?

Generation seems to work OK -- but the order in which the subsystems are listed seems rather unpredictable - and doe snot reflect the nesting within the simulation itself.

I'm using model reference blocks - wondering if this may have an effect, but really new to using the reports, so no real clue here.

thanks !