Yasutami SUZUKI and Yukihisa YAMAO both supported Kadowaki's assertion that the Baekje high official Machi MOKU, who is said to have arrived during the reign of Emperor Ojin, is one and the same individual as SOGA no Machi; but, as Kenkichi KATO and Yoshitane SAKAMOTO have pointed out, there are many historical discrepancies and little evidence to prove the migrant origins of the Soga clan.
門脇が提唱したのは応神天皇の代に渡来した、百済の高官、木満致（もくまち）と蘇我満智（まち）が同一人物とする説で、鈴木靖民や山尾幸久らの支持を得た一方、加藤謙吉や坂本義種らが指摘したように、史料上の問題点が多く、蘇我氏を渡来人とみなす根拠は薄弱である。