[@AirBender] I personally interpreted this area as having rolling hills and tall grass- basically the kind of stuff where you wouldn't notice somebody until they stood up. It's why I didn't make note of Faris or Cloud in my post: Jecht wouldn't have seen them yet. If Edward was one of the first to wake up in our posting order, then he wouldn't see the others, either.

(And Underfoot's a shorty anyways, don't blame yourself for not seeing him)