Ze wife has other things to worry about. Like how her TTK is kinda lazy and isn't doing anything to prep for the next event except resource expeditions, how he's not training Italia, punishing her TTK for mentioning a certain bird as a joke, and other things.
I didn't know Houshou is a petanko, much less concerned about it. How do you even be concerned if you're not aware?
It's a sliding scale, so presumably, it means "how often they actually think about it", rather than "Oh shit! I didn't realize I was flat!" Hence, Ryuujou constantly thinks about her figure, but has come to terms with it, while Houshou doesn't think about it that often, but when she does, she becomes very self-conscious about it. (Zuihou, meanwhile, doesn't give a damn - good for her - while Katsuragi is constantly worrying herself over it.)
Which is exactly his point, RJ is very self-aware she is flat, but she don't give a damn about it.
Taihou doesn't seems to give a single shit about her breasts in her lines tho. She should be on the left as much as RJ. All that interest Taihou is: Health,her curry, drinking, fleet organization.