KC-Y was not the KC-135 replacement, it was the bridge tanker meant to address the shortage of booms in the INDOPACOM CONOP. If you watched the news the last year USAF made a lot of noise until Kendall decided to skip KC-Y and jump right to KC-Z which now defined by USAF as a family of systems. As many other programs are going "family" one can assume a host of requirements that can't be met by a single platform. I would think having several platform will reduce your efficiency but increase your capability. I also believe the KC-Z family will field our first LO tanker.
That is because you are stuck in legacy thinking. The very nature of agile tankers means they don't have to park at Fortress Guam. I give huge props to General Miniham and a few others that are trying to break dogmatic thinking and flip the calculus back on the Chinese. We all know Guam is going to eat 1,000+ missiles on day one so what big thing had been done to protect the tankers? Aside from some Patriots that will tag a few of the inbound shots the only major move has been to lengthen and improve the runway at Tinian, great job you diluted the inbound missiles to 500. The Hudson Institute with no mandate from industry recently completed a Resilient Aerial Refueling Study which outlined the problem and examined the Agile tanker concept. A quick look at the AOR shows 254 airfields available for traditional tankers, lower runway requirement to 5000' and your options more than double, allow for dirt and you have completely diluted the Chinese missile advantage, widened the number of approaches by a factor of three, and allowed for FAR more gas on station.
Potentially misleading, not intentionally and it really relates to the CONOP. Given the distances the KC-135 will have to operate from there is no way it can make it to the potential top off points and give 110K. When you operate an agile tanker closer to the fight, you have to acknowledge that proximity adds flexibility. Operating 500-750NM from a closer airstrip and being able to pass 75,000lbs+ at least equals if not exceeds a KC-135 trying to operate from Guam or other longer runways.
Lets be real, you call bullshit on everything I say on here. I am sure you won't believe me, but having been on the aircraft, I can tell you your assumption is wrong.
Never would I suggest we don't need strategic tankers, that concept has been proven in blood. What we need is new thinking and new ways to flip the calculus back on our adversaries and in my opinion Agile tanker does just that in a multitude of ways.