I'm sure you will be happy to hear that you are in fact wrong ;-). module-starter can add modules, if Module::Starter is enhanced with Module::Starter::Simple and Module::Starter::Smart

Just install the modules above, then create (or add to) a .module-starter/config file in your home directory with

plugins: Module::Starter::Simple Module::Starter::Smart
email: <your email>
author: <your name>
builder: <ExtUtils::MakeMaker or Module::Build>
[download]

then all you need to do is call module-starter with

module-starter --distro=Distro --module=Distro::Modul

to add a new module to an already existing distro