Should units actually move during the AI logic, or separately?

Currently my general logic for anything from turrets to fully mobile units is to do the movement as pay of the logic so can act of it. E.g. a simple form of the turret logic might be:

update_turret ()
{
  if (!_target || ! can_hit_target ())
    select_target();
  if (!_target) // give up
  {
    turn_towards(_idle_dir); //actually move
  }
  else
  {
    auto wanted_dir = direction(_pos, _target->pos());
    turn_towards(wanted_dir);
    if (_dir == wanted_dir) // move
      shoot();
  }
}

Where `turn_towards` considers the current and desired direction, max turn rate, etc.

For fully mobile units there are a bunch of methods mostly calling a `move_speed(speed, direction)` to try and turn and accelerate to a …