Regarding his journey to Suruga and mediation over the family succession, Motoki KURODA's new theory states that at the time Soun was estimated to be 20 years old and his name does not appear in the "Kamakura Ozoshi (Document on battles during the Muromachi Period)," undermining the credibility of the episode.
この最初の駿河下向と家督争い調停については、黒田基樹は新説による早雲の推定年齢の若さ（20歳）と、事件に付いて記している『鎌倉大草紙』には早雲の名が見えないことから考えて、このエピソードの実在に疑問を呈している。