With 30-40k LOC, could you please share the extent to which you feel protected when refactoring given that Clojure is dynamically typed? Some of my colleagues

With 30-40k LOC, could you please share the extent to which you feel protected when refactoring given that Clojure is dynamically typed? Some of my colleagues argue that often times a static compiler is the only thing keeping the ship upright in a large org with a big codebase, and unless your team is small and very smart, it would be foolish to use a dynamically typed language. My experience can't help me much, but I sure want to try it.