We all know that all the people on the earth came actually of 70 nations (even though lots of them became mixed recently).
And we all know that every one of these nations has an angel to guard it. Basically, Yishmael and Edom are not among these 70 nations (Or at least that's what the appendixes in the Artscroll English Tanach shows). But, from commentaries we know that Edom's angel is Satan and Yishmael has its own angel too (the case when its angel came to G-d saying that Yishmael also deserve a share in the holy land since his circumcision was higher than Yitzhak's).
SO how Yishmael and Edom has their own angels if they are not among the 70 nations ?