How many nobles would have aegon needed to bring with him during the conquest in order to get a similar situation that we see in the doomsday book from William the conqueror Reign

Well, William the Conqueror landed with 7,000 to 12,000 men to conquer a land of ~2 million people, so that would suggest that you’d need about 200,000 men to have the same impact as the Normans did on England.