Although Toyoatsu had a younger brother (Toyonori YAMAUCHI, who later became the 16th lord of the domain), he was only 3 years old; therefore, Toyoshige, who was 22 and from a branch family, became a candidate for the position of lord.
豊惇には実弟（後の16代藩主・山内豊範）がいたがわずか3歳であったため、分家で当時22歳の豊信が候補となった。