While it is true that Fusasaki was trusted during his life by Emperor Genmei and Emperor Shomu and was awarded the same Naishin post (government post) as his grandfather Kamatari, considering the general custom that prohibited the rightful male successor to a high-ranking official from holding an important government post, it is more likely that the Southern House was initially the rightful successor of the Fujiwara clan.
房前が生前元明天皇や聖武天皇の信任厚く特に祖父・鎌足と同じ内臣の地位が与えられたのは事実であるが、当時の慣習として高官の嫡男が父親の存命中に高位に昇る事が憚られていた事を考えると、当初は南家が藤原氏の嫡流であったと考えるのが妥当とされている。