I was always told that Y was a second buy of the X tanker to replace the -135 and Z was a larger format tanker for the -10 replacement. Not saying they didn't change the definition sometime in the last 20 years or maybe my info was wrong. AMC also thought leasing 767s from Boeing was a good idea the first time round too.
Has anyone looked at how we are going to get, maintain, and resupply millions of pounds of jet fuel out of an austere location? Yes, dispersing our assets is a great idea for survivability...but each sortie for a KC-135/KC-390 is going to be 200K+ in gas. You're talking millions of pounds of fuel somehow being refilled in a dirt strip...and I don't think an oil pipeline is going to be easily hidden nor is an oiler ship offload facility. This isn't going to be a FARP for a couple helicopters that we can push off the back of a C-130 and keep the Army happy for a week. This COA is talking serious amounts of fuel. I'd just be curious what the plan for that would be or is this a disposable FOB that we will fly 2-3 sorties out of and then bug out back to a hardened facility (that probably would be a smoking hole).