Actually, refactoring browsers were pioneered by Smalltalk people.
Nobody ever talks about that little horror when they bring up how Smalltalk could to refactoring JUST FINE without static types. It wasn't just fine, turns out.
In smalltalk the parameter names are part of the function name to reduce the likelyhood of name clashes. You still have the same problem when you have two functions with the same name and parameters.