There is a practical difference with regard to disqualifying the widow, through his ḥalitza, from entering into levirate marriage in a case where there are other brothers. According to Rabbi Yehuda, who maintains that this individual is certainly a eunuch whose condition is caused naturally, his ḥalitza is of no effect whatsoever, and therefore she may enter into levirate marriage with one of the other brothers. Conversely, according to Rabbi Yosei, son of Rabbi Yehuda, since it is possible that he is not a eunuch and his ḥalitza is valid, she is forbidden to the other brothers as their brother’s wife. לפסול במקום אחים
And there is also a practical difference between their opinions with regard to performing ḥalitza with the widow in a case where there are no brothers other than this tumtum. According to Rabbi Yehuda, ḥalitza is not necessary in this case, as she requires ḥalitza only if her late husband had brothers who are obligated to perform levirate marriage, and this individual is definitely a eunuch whose condition is caused naturally. By contrast, Rabbi Yosei, son of Rabbi Yehuda, maintains that he must perform ḥalitza with her, in case he is a male and not a eunuch. ולחלוץ שלא במקום אחים איכא בינייהו:


הדרן עלך על אלו מומין