I'd rather have 5 very good programmers (using ANY language) than 50 code monkeys (using ANY language). The problem with the Lisp programmers is that they very likely would not be able to work as a team.
I think this claim has no base. I've worked with Lisp programmers and there was no special problem doing so.
I might even prefer 5 average lisp programmers to 50 code monkeys.