IntelliMirror / group policy installations are rather limited in options. Typically, you would not want to try installing anything than pre-fabricated MSI packages, possibly with vendor-supplied transforms allowing for some parametrization of the install process.
While this might be fine for a number of simple deployments (and in the case of Office even for not-so-simple deployments thanks to the MDT), you would quickly feel the limits of it when needing to install this obscure package wich comes with an executable installer accepting a bunch of poorly documented parameters on the command line. Or needing to install at a specific schedule. Or trying to upgrade an already installed package. This is where you would need deployment software like the SCCM where you have significantly more options and a cartload of additional complexity.