Power?

If you are head to head with someone else, they are right you are right, you have a stalemate, if someone else joins in and says well actually you have a point and they have a point but really i tend to agree with you, your power increases by 2 to 1 - if more people join the discussion and more people tend to agree with you then your power increases and the other person is proved to be wrong just by the weight of numbers. But if through that period things could be unravelled and the rightness of the arguments identified would things be different? let's say each of you is making 5points and 3 of your points are good and 2 of their points are good you win - but why not just dump the bad points and move forward together? The next person joining says well i'll keep those 5 points and drop those 5 points and here are 5 points of my own and after discussion we agree only 1 point is worth keeping... how would that help keep us together rather than drive us apart? Debate.