i would think that the two fans are fighting each other. one fan is trying to push the air out of the engine compartment and the other fan is trying to pull air through the radiator into the engine compartment.
another thing that is a little odd to me is a pusher fan being placed in between the radiator and the grill. any cfm it normally creats is being choked by the radiator causing a massive resistance on it before it can draw can even reach the engine compartment area.
correct me if i'm wrong and i have it backwards
I would think that a decent 4000cfm electric fan (puller) mounted between the radiator and the motor, you can get rid of the mechanical fan all together, would be more than enough to cool your engine.
i run a simple summit racing alm radiator with a Derale 4000cfm electric fan, a Weiand alm water pump, and a 180° thermo. I dont have my transmission oil running to the radiator though I have an additional ATI electric trans cooler for that. I take my car twice a year to the Cruzin in Ocean City, MD and trust me that can be stop and go traffic for over an hour. I also race my car regularly at the track and i have never seen my engine get above 190, nor my transmission get above 160.