How many chiefs from Esav does the Torah list?
Rashi to Sotah 13a: The Torah lists 23. And if you will ask that there are 25, 1 Teiman and Kenaz are each listed twice. 2 Korach is listed twice, and both are counted, since there are two Korachs.
Shitah Mekubetzes (to Sotah 13a): The Torah lists 14. Rashi himself (to 36:40) says that verses 36:40-43 name the places, and not the chiefs themselves!
Malbim (to Divrei ha'Yamim I 1:38): There are 16 from Esav and his sons. Also, there were 26 chiefs from Se'ir, and 26 chiefs from Esav stood in place of them. 3
I.e. 14 here, and another 11 in 36:40-43.
Shitah Mekubetzes (to Sotah 13a) differs, refer to 36:18:151:2. Also, Rashi comes to explain the 36 crowns hung on Yaakov's bier. Divrei ha'Yamim I 1:51-54 lists the same chiefs as in verses 36:40-43 here; they were after Hadar died. (Surely the reign of the eight kings spanned more than the years (at most 48) from when Esav left until Yaakov died, especially since the first king and his father were not listed among Bnei Esav who went to Se'ir, i.e. they were born later! - PF)