I like that you emphasized the complementary nature of NIST CSF and ISO 27001. Your point about the emphasis on certification by ISO is particularly relevant, as third-party validation often drives organizations to make sure their security disciplines are healthier. Another thing that reinforces your argument is the fact that NIST offers the hands-on roadmap, while ISO offers the formal structure. You clearly explained their relationship in the next paragraph and showed why so many organizations have success using them together.