I have done previously as you suggested out of curiosity as other people have stated this also and found that my water temps temps were higher when the fans were relocated to the rad as with the size of the core I have the only way to do this realistically is to move the rad further into the engine bay, thus increasing heat soak from the exhaust and turbo. When the car was moving I had no real noticeable increase, with a gain of a couple of degree's of ACT temperature.
I would suspect that your mates were surprised at the results when you did this if your fans were not sufficient to blow through both the intercooler and rad.

My test was not conducted with a gauge it was tested by my collins monitor and I ran anti-lag during this test to assist with high temperatures in the engine bay.

I do not have an open mouth grill, although the bumper is hollowed out in front of the fans to allow air to move round it, my car can sit stationary for a long period of time and still not get temperature concerns.
My car now runs a solid bonnet as such does not have vents to allow air out of the top to add to the problem of heat.

My simple advice would be to try fans fitted both ways and see what works with your setup only then will you know, all I can say if that from experience I think the GRS is well up to the job, and I doubt many people run very high boost with air injectors and anti-lag without a vented bonnet as such I think its good enough for most solutions