Easier for him I guess - he has most of modules. Other modders just kept one for themselves. They of course are useful if you keep changing stuff constantly, and they were really useful back before SVN was used. I wouldn't need anything in modules as I have PPIO and some tools in Notepad++ I think only extraterrestrial stuff could stay modular forever. Of course there could be multiple building or unit files just like wonders, special and regular buildings are separated from each other in core.