Its a bit old (and I have not used it, so don;t no if it will work for you
but DRuby (http://www.cs.umd.edu/projects/PL/druby/index.html) does
static analysis and includes checks for wrong number of arguments
(http://www.cs.umd.edu/projects/PL/druby/manual/manual.html#x1-230006.1.2)

cheers