Earlier as the number of girl cards increased, the applause bonus for extra goal 6 was increased to 20,000 from 4,000 in colosseum (reward changed from Mythic voodoo doll to libido crystals). It seems relevant at that point of time.
NOW after health update, these extra goals are IMPOSSIBLE to get for all players (except maybe for 1 or 2 TOP deck players). So, kindly change your Colosseum event extra goals as well as AI opponent selection that is in accordance with the update changes, otherwise this event has NO charm/fun currently.