A pure functional style does help somewhat; things are more predictable and consistent, expressions can be evaluated inline to test them out, etc. And I think C

A pure functional style does help somewhat; things are more predictable and consistent, expressions can be evaluated inline to test them out, etc. And I think Clojure teams (Lisp teams in general, really) are already forced to be on the small side because of how flexible things can become with macros and such. You have to have a stronger shared headspace compared to, say, a Java project. So that also lends itself to being more dynamic-types-tolerant. Finally, that very flexibility (with macros, etc.) is only fully possible in the absence of static types. So there is a genuine tradeoff. Still, even with all of the above I'd rather have them than not have them.