This has been an engaging and enlightening discussion, just the sort of thing a “working” thesis such as mine was intended to stimulate.  I agree with Ephraim Radner that the ABC does in fact possess more powers than the thesis credits him with, just as I think Bagehot understates the powers, rights, and political influence that the Sovereign can (still) exercise in the current constitutional arrangements of the UK.  The point remains, however, that the cultural norms and expectations of the ABC’s English milieu tend toward a Bagehotesque analysis of how the ABC relates to the powers he possesses; reticence seems to me to be built into the DNA of the CofE.  So the question I’m interested in answering is:  Why does the ABC act (or not act) in this way rather than another?  The best answer I have been able to come up with is that his leadership style is a combination of cultural expectations of a Bagehotesque variety with regard to how primatial authority is to be exercised and a personal aversion to anything that could be called coercive, though again Ephraim Radner is quite right that “coercion” is a mushy category if taken beyond the literal sense in which Benjamin quite rightly employs it.