lasken – “The names were based on a story where the wife was mixed up with the mother in law.” Where did you get that fairy tale from?
Certainly not the Noda B’Yehuda Shu’t Even Ha’ezer II #79 (that discusses and discounts the Tzavah, saying it would only apply to Rabbi Yehuda HaChosid’s descendants).
Indeed, the Noda B’Yehuda also proposes that the concerns of Rabbi Yehuda HaChosid apply only to birth names or names given to sons at their bris, but do not apply to any name changes that take place afterwards. (This militates against the concern you mention of mixing up people- as such a “concern” would apply also to changed names that take place afterwards!)
Please do not spread misinformation, as Trump would call it Fake info.