I had the understanding that static pressure is the pressure exerted by air or water, in our case air. Fans that are 38mm thick usually provide more because the blades are deeper?(couldn't find a word for that) and that is what helps high FPI rads like the GTX and GTS shine because the 38mm thick fans have the PRESSURE to push through the high fin density of the radiator. Correct me if I am wrong because I am just going with what I understood static pressure to be.You want less static pressure. Static pressure is the resistance to airflow.
Unless there is about 1/2 inch distance or more between the fans and the rad (use of a shroud) when a fan pushes air at the rad several things are happening and you can actually see it with smoke and a low speed fan. First thing is the air is very turbulent moving almost in a swirling motion as it moves away from the fan. This is due to the rotation of the blades imparting a rotation in the air stream and just the "disturbance" of the blades both pushing and rotating and "chopping" the airflow as it leaves the blades. All this motion is not in-line with the fins. Second is that there is a significant "dead space" right in the middle where the fan hub is. There are on blades there so very little air gets pushed outward from the fan in this area.
Pull creates an area of low pressure behind the fan (in between the fan and the rad) which sucks air uniformly through the rad across the fins with no dead spot and a much more uniform flow. Usually this works best.
Even more important than above is to feed the rad as cool of air as you have available even if it means the rads will be blowing air into your case. I did not look at all the post so not sure what you are up too but the good news is even if you do it completely wrong it will still work well.
If possible/convenient it is almost always best to pull cool room air through the rads. I say almost because if the fans are very low speed it matters less and there are always mounting issues to be considered. Sometimes the best way is not the best way.
Looking at your pic above, if I understand it correctly I would flip the bottom fans around to pull and you are good. One push one pull is bad, you even show with your arrows how the warm exhaust from the lower (heat rises) rad could be sucked in by the upper fan. Fans then rad then case with fans pulling air from near the case side panel through the rad and blowing it away from the machine. That would be my first shot. And the good news is that as long as you do not arc weld anything, you can change the configuration fairly easily with longer standoffs different screws etc. if you want to see what a change does. I really like that you are not hung up on hiding the rads. From a temp viewpoint your proposed setup is almost ideal. Only thing better is both on top laying flat but that is impossible as there is not enoubh room.
Best shrouds are empty fans lol. Ghetto but effective.