You are forgetting that this is a PRE-Production Vehicle - and many items in this vehicle will not be indicative of the final Production car. For example, the RHD center console was probably not yet available when this car was hand assembled.
Apart from the 5.2 GT350, could there also be a High Performance version of the 5.0 in the wings ?
Note how the "High Performance" version engine is differentiated from the regular 5.0 in the Parts catalogue below.
6007...
In the case of the Ford GT-F, the numbers are seriously UNDER rated:
Official Ford/FPV figures for the GT-F are (only):
351 Kw (471 Hp) @ 6000 Rpm
570 Nm @ 2,500 - 5000 Rpm
http://www.fpv.com.au/downloads/gtf_specs.pdf
http://www.fpv.com.au/gt_showroom/le_gt_f
Dyno Test - Shootout Ford...
Ford Introduces Innovative Airbag Design on New 2015 Mustang
Ford Introduces Innovative Airbag Design on New 2015 Mustang
https://media.ford.com/content/dam/fordmedia/North%20America/US/2014/06/19/2015FordMustang_PassengerKneeAirbag.jpg/_jcr_content/renditions/cq5dam.web.1024.768.jpeg...
At least the Cats tail seems to be out of the bag !
That would seem to fit, as 5.2 L is apparently the Max the Coyote can be safely Bored (re sleeved) to.
You are confusing a Flat Plane Crank engine with a Horizontally Opposed (Flat) engine as used by VW, Subaru, Porsche etc. They are not the same, with the FPC retaining the traditional V Formation..