I thought of that too, but I wasnt gonna bring it up unless someone brought it up. Since you did;

5) Jenova crash landed from space and made a massive crater in FFVII. The crater on Trabia of which Serapy and I speak is a referance to the northern crater, or perhaps THE northern crater.


SIMILARITY
In FFVIII, monster swarm from the moon and crash land on the earth. There is crater in Trabia (Jenova made a crater in FFVII via crash land) that these monsters caused. This also occured in the Centra continent. (which brings up something else, I believe the ancient race of Centra are in FFVII too).