I think you guys are not thinkly clearly. Why is this so hard for you to understand? Air enters the front of the radiator either passively (below 185 degrees, the fans are off) or actively PULLED through (above 185 degrees) and exits out the rear. When active, the fans pull air from the entire surface area because of the shroud, blowing the heat into the engine compartment. All of this is exactly like 98% of the OEM market and aftermarket radiator systems. Don't believe me? Check out Griffin radiators or Jeg's or wherever. Bottom line - Shrouds are a must! Check out this month's Four Wheeler magazine too.

Also, the fan is not directly against the fins. I just laid them on there to get a feel of the overall dimensions. The fans come with little springs to keep the separation about 3/4 to 1". Thereby drawing air from the entire shrouded surface area, again just like OEM. I bet you didn't even notice the weather stripping holding the shroud even further out either. It can be seen best near the bottom tank.

PK, you really need to rethink your logic. You have two contradicting statements - "But by far the greatest amount of cooling is needed when you are travelling at highway speeds (NOT TRUE AT ALL), uphills (TRUE)etc, when you have the gas pedal to the floor.
At these times the fans do little, or no work at all. The air flow through the entire radiator frontal surface caused by your forward motion is enough to cool the engine (THIS PART IS TRUE)."

Again, Four Wheeler has a great article if things still seem unclear or try Pirate4x4 - Bella Vista's The Cooling Bible.