The problem with those range rings is that they depict theoretical COVER, and not effective and efficient AIR Support.
We used to have pretty effective and efficient operational air support with neighboring units covering each others in the event of down time.
What we have today is a mere shadow of that earlier effective operational support. Transit times can now be far too long, and the resultant effectiveness on arrival markedly reduced.
We are not far off of losing it all together. Who wants to pay for the toy now that the theorists and accountants have broken it?
TF