And that pretty much confirms, not disproves, the idea that "males tend to be bigger". If you want a take-home message of great simplicity, that's it. It was right all along (just overstated).

(Note that much of the 39% would split into "males slightly larger" and "females slightly larger"--they are "the same" largely because they have small sample sizes and chose confidence intervals as how to decide whether a species has sexually dimorphic size. If they had more data, the confidence intervals would shrink and more calls would be made as "male bigger" or "female bigger".)

If you have room for a more sophisticated view, "Males tend to be bigger, but the tendency is certainly not universal across species, not that strong for many species, and some females are larger."

Your discussion is fine, but your top-level characterization is more misleading than the original characterization.

(Yes, it does mean more work needs to be done to understand the evolutionary determinants of sexual dimorphism in body size.)