From the fact that Yoshihisa adopted the name Tadayoshi at first, thereby identifying himself with his grandfather, and later took his grandfather's daughter for his legal wife, it can be presumed that he was greatly influenced by his grandfather.
義久は初名を祖父と同じ忠良と名乗り、祖父の娘を正室に迎えている事からも分かるように、祖父から大きな影響を受けたものと推測される。