What exactly do you mean to be the Perl equivalent of "stringly typed" coding? Passing comma-delimited strings instead of arrays? Because "passing a string where you should use a float instead" doesn't really apply to a language where "a scalar is a scalar is a scalar", regardless of whether that scalar is a string or a number or even both at the same time.
As for the actual question, my approach to similar situations is to try to show better ways of doing it (TIMTOWTDI, but not all ways are equally good!) and explain why they're better. That doesn't really work with typographical conventions for names, though, so I think you'll just have to go for the "this is the standard convention" angle and hope for the best.