And a link to a story that has their size differences:

https://www.bjpenn.com/mma-news/craig-jones-puts-career-on-the-line-in-intergender-grappling-match-with-gabi-garcia/

Admittedly it could be mostly due to him just being a better fighter... :D The funny part is that there seems to have been some opposition to that fight before it happened not because it was a man against a woman, but because she is so much bigger than him. Presumably they thought it would not have been fair. To him.

And a link to a story that has their size differences:

https://www.bjpenn.com/mma-news/craig-jones-puts-career-on-the-line-in-intergender-grappling-match-with-gabi-garcia/