Ah, but DLC have a "Different" infra-structure.
Providing for scripts is more about linking miscellaneous assets *FROM* their own folders -- but, within the Steam overlay verifier. Indirectly, it is an extra Config.ini specifically devised to maintain assets on a regular exe call *TO* runtime stackspace.
Example; if you were to create a scenario method (Such as Polynesia) to replace the Iroquois_Aztec_India pool with some real leaders similar to Kame-- you'd need to refer new assets within the packaged MOD of a DLC context.
As my earlier point made, the ADD or REPLACE elements comes into play and if a single item is missing (by script or otherwise, btw) the whole project can fail Steam verification.
Even more so once the usual auto-updates start fooling around with installed files.
In conclusion, it's not that Modding everything isn't allowed -- it's that specific ModBuddy conditions (and minimal features) aren't available or were simply kept away from us.
Given the extensive knowledge & skills some of us already have, it's only a matter of time until *WE* find what we need to do whatever is necessary.
Firaxis told everyone *THIS* Civ version will be the most moddable ever - should i insist.
We're still waiting and not for the silly DLL only, btw.