This question mentions that in Israel, when Simchat Torah is on Shabbat, Vezot Habracha is divided into 7 aliyot, followed by Chatan Torah and Chatan Breishit.
I'm curious as to why they don't make the 6th aliyah Chatan Torah and the 7th Chatan Breishit. It's not as if this idea of having the 7th aliyah from a 2nd Torah isn't done on other occasions such as Shabbat Shekalim, Hachodesh or Chanukah which may occur on Rosh Hodesh. The 7th aliyah is read from the 2nd of 3 Sifrei Torah.