Which one flows better, factory 6 blade water pump or 8 blade

I'm aware the so called A.C. pump has 6 blades while the non A.C. has 8. It would seem the 8 would move more water hence a cooler running engine. Seems like the air cars would need the better flowing unit. Also the Mopar bible recommends the A.C pump for a HP build, stating less drag. What gives?