Regardless, that's still a lot.
Not including sounds, models, images, default save, etc:
Gamemode_Civilization: 271 KB (278,141 bytes)
Gamemode_Space_Mod: 254 KB (260,217 bytes)
It is absolutely possible to wind up with a mod that extends well into large fractions of a megabyte, just through its text files alone.
Mind you, this is spread across more than a dozen files, in both mods, but still.