i think (and very rarely do i do this) people change positions but not belief. one holds a position with current information i.e. current understanding of current data available. one changes position when new data is available or a new understanding of old data is arrived at. since belief requires very little of this, it is hard to change.
and sometimes love just ain't enough
When I did my training, I qualified in Youth Work and Ministry. I did an assignment on apologetics and concluded that no smart arguments won anyone over. Love is the best evangelistic method. People who want to argue just want to argue.
be careful to discern arguing with rational points of view, and don't assume that a point of view here that is a direct rebuttal of another is one arguing just to argue.
as to your point that no smart arguments won anyone over, that is religion. smart people recognize it is belief. others rationalize based on feelings and beliefs, not facts.
if a "smart argument" does not make another think, they might not be smart.