Altho trained on heavyjets in the USA, I must admit that the "ground pointer" is/was not a bad idea. Also have flown aircraft with ground pointers on the pilots' ADI's and sky pointers on the standby ADI. Hmmm, not a good idea but it was allowed by a certain (third world) regulatory authorty. Never found it much of a problem to operate from one day to the next with different displays. Same with Collins "V" bars or Sperry crosspointer F/D displays.