When men ask this question they can't see their own hearts let along others. So then our works, in the flesh, are judged by one another and a competition of who is better begins. The Lord Jesus answers the question in verse 26 "...and he that is chief, as he that doth serve". The Lord Jesus Christ is Chief and in his person He served his people unto death on that cruel cross. Why even ask "which of them should be accounted the greatest". Put your eyes upon Jesus and take them away from yourself.