A Metaphor for ... What?

Some time ago, I learned about a descriptive term for a common phenomenon in intellectual discourse, invented by Nicholas Schackel of Cardiff University. Commenting on the phenomenon and providing examples of "Motte and Bailey Doctrines", Scott Alexander describes them as follows:

[A] motte-and-bailey doctrine is when you make a bold, controversial statement. Then when somebody challenges you, you claim you were just making an obvious, uncontroversial statement, so you are clearly right and they are silly for challenging you. Then when the argument is over you go back to making the bold, controversial statement.

Some classic examples:

1. The religious group that acts for all the world like God is a supernatural creator who builds universes, creates people out of other people's ribs, parts seas, and heals the sick when asked very nicely (bailey). Then when atheists come around and say maybe there's no God, the religious group objects "But God is just another name for the beauty and order in the Universe! You're not denying that there's beauty and order in the Universe, are you?" (motte). Then when the atheists go away they get back to making people out of other people's ribs and stuff...

As I read the above example and some of the others, I had an "Aha!" moment, because Schackel has definitely characterized a common form of responding to challenges. That said, I am not so sure about referring to these examples as doctrines so much as tactics, or even reactions. Nor am I sure there is a single phenomenon being observed here. I say this after reading the following from Alexander's analysis:

[I]n motte and bailey, you're unfairly replacing a weak position (there is a supernatural creator who can make people out of ribs) with a strong position (there is order and beauty in the universe) in order to make it more defensible.

I wouldn't call that a strong position because that's hardly a position at all. It seems that in some cases, as in this, the motte relies on the opponent filling in whatever (probably) warm fuzzy meaning he will for the "strong 'position'", while in others, there may well be a strong position, but any of the following might apply (See PS.):

1. The strong position supports the extravagant-sounding claim and the individual sees how it does, but also sees a need to lay the groundwork for arguing in favor of the claim. But his challenger storms off in a huff before he can get a word in edgewise.
2. The strong position supports the extravagant-sounding claim and the individual sees how it does, but he does a poor job of articulating that support, or otherwise helping others see the value of that point,
3. The extravagant-sounding claim again follows, but the individual does not really understand how. He further may or may not really grasp the strong position.
4. The strong position does not actually support the extravagant or extravagant-sounding claim. The individual may or may not realize this.

On considering such cases, I am even more unsure about calling something a "motte and bailey doctrine" or of whether the label is even a useful description, covering as it does (or I think it does) an entire range of common responses to intellectual challenges, from proper to mistaken to evasive.

-- CAV

P.S.: This assumes, based on a comment I ran across, that this can sometimes be observed when an extravagant-sounding claim follows from a true premise. Alexander's use of "unfairly" seems to rule this out, but Schackel cautions against calling this a fallacy. (Not that it not being a fallacy necessarily makes the description "motte and bailey" apply to my first category.)