How much does Nintendo of America really do? It's basically localization and marketing, right? And maybe outreach to third party developers?
I would imagine they're able to underpay due to the allure of working for Nintendo combined with a lack of actual positions.
It's considered tech, adjacent to The Pokemon Company, also in the same area...
It's not just localization and marketing they do have corporate IT and some development/studio as well as very poor security policies that gets them breeched every now and again which makes sense, they pay poorly and from my personal experience gatekeep but that makes sense from the applicants that probably get in their applicant pool.
I'm sure they've employed an army of lawyers for US IP law which isn't something easily reproducible in Japan.
They do have at least one development studio there, Nintendo Software Technology:
https://en.wikipedia.org/wiki/Nintendo_Software_Technology
They also make quite a few more changes than expected when localising games. Or at least they did in the olden days, where the American versions of games sometimes had different/extra features compared to the Japanese originals.
I think some of the localisation team are also regular voice actors for the games, on a worldwide basis.