Majority of people in the Sahel (sub-Saharan region, for example: Chad, Sudan) are employed in agriculture, which is the primary sector in the industry.
So the mistake is: not "secondary" but "primary"
The purpose of the Heavy Industrial Zone (I-1) is to provide for industry where access is available to transportation routes, transportation facilities, and public service facilities and where surrounding land use and the environmental setting will permit most industrial uses without major adverse impacts.
Commercially zoned areas are generally reserved for businesses that have some kind of interaction with the public. These may be offices, retail stores, restaurants or bars. Commercial zoning can also include hotels and apartment complexes.
Idk what following people you’re talking about but proketariat is the working class who do not have properties