On top rope? No big deal at all. My 100 pound girl friends belay my 200 pound guy friends on top rope all the time. My 90 pound girl friend lead belays me with no problem. As long as they're competent you'll be just fine.
In the TR situation described, as long as the belayer had good footing and was close to the wall and under the anchor, I'd not worry at all. If it was an uneven area or there was potential to get dragged, I'd sling someting for a ground anchor. Even a 30-40 pound rock would do.
My first lead fall was caught by a 90 pounder. I'm about 180-190. She didn't go anywhere and it was a hanging belay, 7 foot fall, 12-15ft of rope out.
I think he's just trying to keep up with the typical American man. See, the typical American man (meaning, your non-athletic, McDonald's feasting, 12-pack during the game type) has 1 woman that weighs 190 lbs. Austin is smart enough to divide that weight into 2 women - which sounds like a load of fun most of the time...but also means that he has to deal with twice as much PMS.