That's true. Same has been & can be said about the written Koran. Mohammad himself (a bedouin Arab) was said to have been illiterate.
They have nothing to do with Allah ~ more like minor cases taken to authorities to resolve disputes Kind of like using traffic court instead of legislative bodies ~ amateur judge made law is what it is..
Allah, itself, was a pre-Islamic deity in Arabia, but then chosen & accepted as the God by Mohammad, his immediate disciples, and moslems, as part of Islam.
I wouldn't say "minor cases" regarding Sharia at all. Broadly, 2 sources are used for Sharia law. One is the Koran, and the second, the Sunnahs "traditions of the prophet i.e. Mohammad". Sharia deals w/ many topics & elements that secular law deals with. Inclusive of various crimes, politics, economics, family & social matters, adultery, dietary requirements, prayers, fasting and so on.. Sharia law is very codified & Islamic scholars, muftis or mullahs, are required to be trained & well versed in these laws.
But, the fact that Sharia is not only based on theology, but also on pre-Islamic Arabic culture can't be denied. Similarly, it has borrowed some elements from preceding religions in the ME.
Still, outside a handful of special cases (which were probably created out of wholecloth by the “scholars” in Damascus who started the ball rolling, the materials arose out of actual practice ~ in the courts ~ that special training came centuries later AFTER the law was locked in place.