I don't think there's really a hard and fast rule. Generally, I try disassociation first, then slide or shift as needed. Monica Paz pointed out to me in a class once that apilado doesn't have to be full on front to front. Depending on the broadness of thed leader's chest (and/or belly

) the follower can be slightly sideways. Or if you are walking outside, or leading the follower in a circle walk around you, it is way more comfortable for her to sideways lean a little, so her hips can face away. As always, adjustments are made to the comfort of the partners, and what may work with one person won't work with another. I think when we've danced before Peaches, there has been a little sliding. But it's usually masked in the motion of another step.
Hmm, I've been thinking about this one so I'll start with what I know
from personal experience. Like Mario I too have watched Ricardo Vidort
videos, with some admiration I might say. And like plugger I was taught
to release the hold and slide gently to an offset position to walk outside.
But I don't like it, it's ugly and clunky. And I was taught a similar thing
earlier in ballroom for outside movement in the quickstep and foxtrot
ending up hip to hip. It again is ungainly and leading locksteps entails
a hip displacement (I could be stronger about it). Ballroom has contra
body position and tango has disassociation to solve it so I've come to
the conclusion that such offsetting (or sliding in tango) techniques are
teaching aids to get people used to the idea but ultimately you will see
all good dancers, amateur and professional, use a twisting of the upper
body to maintain connection.
It needs to be learned and requires suppleness of the spine. So some
carrying injuries or damage may never be able to and, yes, we have to
adjust for that or recognise that some movements may not be possible.
Walking outside on the closed side of the embrace is the most difficult
and, speaking as someone who has intentionally developed the technique,
it can take a partner by surprise and she can resist. Often it's not because
a partner cannot but no-one may have done it before. A really good lady
will just follow the chest and allow it to happen.
One thing my teacher pointed out to me once... there are always small adjustments done to the amount of lean you are in. Even in close with no weight sharing, if the connection is good there are dynamic moments when one's balance is dependent on one's partner.
Yes I agree with the adjustments but not so far as balance being dependent
on your partner. In writing it's difficult to judge what you mean and maybe
you are talking about an ever so slight dependency. If I'm ever aware of
my partner's balance being dependent on me, it's already gone wrong unless
I've initiated an off-axis movement which is then the intention of course.