The 100,000 smaller reactors can still be put in the same place as the 100 giant reactors to make inspection and monitoring easier. The modular design makes incremental capacity upgrades easier, makes maintenance and repair easy, and helps to put more testing and QA on the modular design. Just think of it as 100 locations where you can either have 1 giant reactor each or up to 1000 modular micro-reactors.