hi As per ICC rules teams will be ranked a1 or a2 based on seedings andn no as per points table.The purpose of this is so that viewers can know which date is their country playing and make their travel arrangements accordingly.Here a1 doesnt means first place it just a tag given as per seedings.If one of the minnow countries knock out a seeded country then the spot will be given to that country.So if south africa is knocked out by ireland say it will be given the A1 tag.ITS purely for making travel arrangements easier and nothing else.