Let me suggest that what cuts across all types of glider, angles of
attack and back, phases of flight, is the goal of the maneuver. Both
the CFI-G referred to in the OP, Paul, and most others agree that they
wish to perform a coordinated turn entry (setting aside circumstances
where slipping is advisable or fruitful). So, in teaching, why not
stress monitoring methods first -- primarily visual (yaw string staring
in the face for just that purpose), and then also aural (screaming
vent), kinesthetic ("falling" to the inside is a classic sign of
slipping to avoid initial discomfort at leaning from the vertical,
"cracking the whip" a danger sign), control positions. So, "leading
with the rudder" could be appropriate IF IT WORKS, but how about making
it an incidental discovery, a consequence, as opposed to a primary cause
or goal. In introducing maneuvers, I favor discussion and demonstration
(student following through) of "it should look like this" before
admonitions of "move this to there to achieve that goal". Also, even
following RUAC, I favor avoiding "always" and "never".

--JHC