Patrick, I think the difference may be in where we place the "precision". To your point, the tip size wouldn't matter if the cue tip strikes the cue ball ON target. What I would argue is that the use of precision is in striking the cue ball at the intended point.Repeating the claim doesn’t make it true. Why does a smaller diameter miss more (hint: it doesn’t)?
P.S. The bigger the margin of error, the less precise you need to be.
pj
chgo
Take the tip size down to 2mm, for example. If the contact patch is in the same location as a strike with a 13mm tip, the resulting ball paths should be the same for both. But, having a stroke that delivers the tiny tip to the same point is going to be harder. [This makes me think that it could also be argued as one not being harder than the other, but remember, we're considering an inconsistent stroke ("APA4")].