"As I’m sure you could tell, I get a little heated when I hear 'war is war'. A broad generalization that at some levels works – e.g. reacting to an ambush is reacting to an ambush, firing an artillery mission is likewise – but the approach is unhelpful when it bumps up against reality at the Title X/Generating Base level."
With some experience in the force generation business, I understand your point but do not fully agree. The issue is to deliver competent forces to the battle area. My contention is that we have failed at that in the past to one extent or another (to include both current theaters) but we recover well.

One can and should make the point that we should not have to recover -- I agree but reality intrudes. My seeming digression into the training regimen, the discombobulation of the cost those serving pay for the life style we have and the Army's penchant for wrongful focus on occasion were all based on the fact that such failures are a fact of life and that we have (purposely, inadvertantly or by default is immaterial) elected to operate that way. It could possibly be changed to preclude that in the future but I'm doubtful of the true possibility and dubious that will occur.

Thus, IMO, to say the Title X responsibilities dictate that 'war is not war' is not stating an immutable fact, rather its a euphemistic phrase for 'it's really difficult to be ready for everything.' With that, I totally agree. I'd also submit that to do less than be prepared for everything to the extent possible in spite of the difficulties is a disservice to the nation, to the Army as an institution and to the troops. But that's just me...

WRT:
I suppose the question is what level of competency and whether you buy into the argument that we are in an era of persistent conflict, and that we will continue to conduct these types of operations (although admittedly to varying degrees of scope). As well as what that means wrt the aimpoint/weighting of training effort and said resources with regard to time, personnel and training resources.
I think "buy into the argument" evades the point which to me is to be prepared for that to be the case. As Casey Stengel said, it's hard to make predictions, especially about the future. I have no clue whether such will be the case but I think it would be terribly remiss not to prepare for that at some level just as it would be terribly remiss not to prepare for a big war. It is not hard for me to say we have an obligation to be prepared for whatever the future brings; it is very hard for the Army to do that and I'm quite cognizant of that fact. Where I think we differ is that I'm pretty sure it can be done -- but that means breaking some Rice bowls and that is never easy (though I'm a long standing proponent of just such crockery smashing).
"As you surmised I think COAs 1 & 3 are more or less throw-aways but for different reasons (unacceptable/unfeasible respectively). However, I think it is unwise to assume we can continue on our current path COA 2. When viewed through a strategic lens, the US has passed its culmination point (specifically wrt to ground capability, but it appears the same is true wrt to maritme and air operations)."
We can disagree on that. I agree with those other bright people

We will never be able to account for all contingencies; no democratic nation will -- and that's okay. What we have to do is be prepared, as best we can, for the likely contingencies. I submit our current capability to do that has been lessened but it's a long way from being in the tank. The doctrinal culminating point and many prophets of doom fail to account for the human dimension, the young guys can adapt. The issue is; will the old guys adapt?