It's not going to work. The basic theory is flawed. This is not how you build a broadband network that will be future-proof. Any kind of mesh network is likely to get congested instantly, and not do what they think it'll do.
There are ways of building a mesh network that will work. For a start, use the commercial, licensed 4G spectrum that should already have been assigned to the operators who know what they're doing, and don't use the mesh to backhaul the signal at all, but link lots of basestations with fibre to get the bandwidth density (Gbps/sq km) that's going to be required. Basically, build a 4G cellular network. Otherwise, all they're going to have is a giant WUG with the performance of dial-up, or, at best, hotspots that work when there are no users, and are useless otherwise.
If anyone from the Western Cape government is reading this, PLEASE don't build this monster - just get the private sector to build competitive networks (fibre included). We know that works. What party do you think you are? Remember there's an election coming up. Don't you dare use our money for this government intervention / state capitalism nonsense.
At the risk of sounding trite, if this kind of magic worked the way you're imagining it, don't you think it would have killed off all the world's mobile broadband providers by now?