If an Army HQ accepts its orders and all subordinate leaders are on delay that turn ...
I am not sure I understand your question.
Army HQs accept orders entirely separately from their subordinate units (ie the Corps or Divisions or Brigades).
But there is no Command Range that applies to Army HQs. An Army HQ is free to wander over the map (except that artillery units assigned direct to the Army HQ have to keep within 8 hexes (6.11.1)). So if your Army HQ accepted a move order and the subordinate Corps were all in delay, then the Army HQ would move.
Corps, divisions and brigades are different, but you asked about the Army HQ unit.
Edit: which Scenario are you playing in Talavera?