Well Brian A is in seclusion at this point so my feeling would be he would say:
As the go to for restoration parts for these Shelby cars in 70'/80's, then Ford wanting a DOT approved MKIII type car to add to there other small manufactured batch cars like the BOSS, Pantera, Intermecanica etc... It was more of a fit than a total re-design.
Dunno but I agree they had there differences but so did CS and KMS, all Replica MFG, Gelsco, HiTech tec...
No stone unturned...
I understand your comment better now!