I can't really tell you the why, what i can tell you is that i bought the alrad radiator and dual fan set up and it solved all my tempeture issues,plus excellent service, easy install and they look great.
80$ for dodge intrepid fans, still the copper radiator and it will cool just as good or better than the best out there. Spend money in getting the airflow through the radiator...that is the ticket to good cooling.