It would be interesting to see the results of something like a Super League laser measurement comparison of the two guys...
By definition, the guy who is smaller by volume of total measurement IS denser though. Willing to wager a substantial bit that is partially due to several additional pounds of bone matter internal to any heavy PL guy with a long history.
PL folks can and do develop physical oddities that are far outside the norm due to the outrageously high habitual longitudinal loading of the skeleton etc...
Same for even recreational lifters sometimes... Rippetoe had a middle aged female who was examined repeatedly because the docs felt hardened lumps in her abdomen. Finally an MRI showed that what they were palpitating were very large, well defined, rock hard ab muscles from years of PL training under a nice layer of middle aged pudge.