Have you read his work, studied his sources? Which specifically, his data and sources are not valid? It's valid to question it but without your own research, your opinion on the matter holds absolutely no water, no matter how you word it or what you want to believe. I know Dave Parsons, friends with Cooper, worked with him, he knows his research, valid as can be with what is available. Who are these authors you have spoken to, what are their names? Funny how skeptics abound but never have their own data to back that skepticism. I welcome anyone to research the matter, present a valid contradiction to his work, gives for a more accurate account of the history. Until then, his research and numbers are what they are.
Dave "Hey Joe" Parson is co-author on this book:
http://www.amazon.com/Grumman-F-14-Tomcat-Reminiscences-Service/dp/0760339813
I can give you or give him your info, he can put you in contact with Cooper so you can discuss your issues with the validity of his research. Let him know why you think it's not valid, why your "friends" have issues with its validity and you guys can discuss it.