The problem with most electric fans is that if they get a little flow resistance in front of them, the actual flow drops into the toilet. Radiators create considerable pressure drop as air tries to flow through them, especially 2 and 3 row ones. So most fans are going to crap out. I have tried to dig down into much of the fan literature to get the flow versus pressure drop curves with little success.
But, if you have thin balded fans, then they have this characteristic of the flow going to heck with any real pressure drop in front of them. The air just flows from the back of the blade around to the low pressure area in the front of the blade and just keeps going around and around.
There are some very successful designs of electric cooling. I raced a Mitusbishis Starion for along time for a long time and it cooled fine with the factory fan setup, even with the HP upped to 275 Hp from 2.6L.
Can you tell us the brand of the fans? Have a pix?