To recap... My understanding is that in the early 1980's the F15 was perceived as having capabilities vis a vis the NORAD role that no other USAF air craft had.Can the F-4E not achieve the same air dominance even in the face of flankers and fulcrums as in the OTL ? Was the F-15 really needed ?
I realize that at first glance on paper the F4 and the F15 may seem to have similar abilities in the interceptor role but I suspect in practice the F15 had a lot of advantages that may not be apparent from reading a summary of the specifications.
I would expect the differences against other fighters would be even more pronounced.