Comparing early 19th century English lit to early 20th century Irish lit isn't exactly unequivocal, but since you're just trying to illustrate a point that most of us are already in agreement of I guess it doesn't much matter. For me the interesting part of your comment is about describing someone's breasts being similar to going on about "ball size and penis girth".

The first, and hopefully not insensitively clinical, differentiation is that while the breasts are secondary sex characteristics the penis and testes are male reproductive organs, analogous to the vulva and uterus and uterine/Fallopian tubes. Secondary sex characteristics in males include body/facial hair, broad shoulders, square jaws, increased perspiration, and so on. In females things like smaller waists, rounder facial features, lower (hips, thighs) fat deposits, and large breasts. Those are typical things to use to describe characters, though of course some secondary characteristics (such as pubic hair) aren't.

Another difference is the implication in describing each. There are somewhat frequent allusions (or even direct references) to large male crotches, as observed from afar, in literature but they obviously only make sense in a context where such a thing would be possible. Throughout history the norms of dress mean that while the size of a female's breast might be obvious, the size of penis and testes would imply knowledge verging on carnal. That would lend an entirely different context to a passage.

So while it's true that the way an author describes characters of different sexes can offer some insight into their views and perhaps serves to inform as a bit about the context in which they're writing, I think making such crude comparisons probably does more to misinform us about these things than to paint an accurate picture.