It seems that entrenching has no combat penalties and no associated costs (since there doesn't seem any modeling for fatigue or resource consumption related to entrenching).
Thus, as far as I can tell, one should always entrench when stationary. Even if you are in an offensive posture due to leader activation, you can end up implicitly with a defensive posture.
That brings me to the point of this ... if it always better to entrench and there are no penalties, then why not make it automatic?
Other games have implemented this automatic behavior for stationary units. Examples:
Panther Games: RDOA/HTTR/COTA - the deployment cycle begin as soon as units stop moving.
Firaxis: SMG/SMA - stationary units not engaged begin to improve their positions.
Paradox: HOI 1/2 and Victoria - again when not on the move they dig-in.
Comments?