Chrysler used the 6 vain pumps on AC cars for this reason, remember there was an AC condenser in front of the radiator that isn't there with non AC cars. The condenser is not only restricting airflow through the radiator but it's transferring it's heat to the radiator so, Chrysler slowed the flow through the radiator to give the fluid more time to cool.
Nope. As Kunkel stated above, it’s to increase airflow while not increasing the opportunity for cavitation.
