This is what I do, have done the PV Green Card Installation Course. This is what is recommended. A fuse on the Positive and Negative legs, a surge protector and a Double Pole Isolator switch. See drawings below. No fuses on the roof, only connectors where you can disconnect if needed. If you disconnect make sure the fuse on bottom panel are disconnected as it can cause big spark. Earth the Solar panel structure and connect to a separate earth Pin, 1.5mters so that lighting would be taken direct to ground and not to Electrical Earth.
I ordered all component's from Solar Europe in Pretoria. Solar Europe - Solar Energy Brands Importer and Distributor (solar-europe.co.za)
07 Panel PV Isolation Layout.pdf 08 Panel PV Isolation Layout.pdf