This does seem to be the traditional milonguero way.they would make 8 single time steps in a phrase,
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
sometimes they do more steps, if they do double-time steps, but never fewer, even though sometimes the 3 would be unaccented.
It's one aspect of video of Ricardo Vidort which shows a rhythmic dance
and the tunes selected to dance to are strongly rhythmic too. Rarely did
he seem to visually respond to the melody though I can only suspect
that the melody (and the lyrics maybe) influenced how he felt to his
partner, the rhythm being danced with his feet and the melody by his body.
Maybe it's the coming of artistry and artistic teaching that introduced
visual dancing to the melody or even different instruments.
However it is the rhythm that both partners hear most clearly and it therefore
provides an audible connection; maybe that's what those ladies are used to.
Coming from other dances I could go on at length about the role of rhythm
in the creation of dances and the consequences of separating the dance
from its music.