In addition, some people guess that this family tree itself was 'created by later descendants who felt unnatural to emphasize the maternal line, although it is no problem to identify itself as descendants of the Kojima family because Hisaie was a real son of Muneie and his mother was an origin of the Kojima family.'
さらに、この系図自体が「これは久家は宗家の実子であって、一応は母親が児島の人間ではあるので児島の後裔を称する事に問題は無いのだが、やはり女系の系図の方を強調する事に不自然さを感じた人間が後付けで作り出した系図では無いか？」との意見もある。