I think the lack of depth is already starting to hurt the Trojans, making them the most vulnerable. Stanford's smash mouth, 3 yards and a cloud of dust style of play makes them both tough to beat and vulnerable to upsets as the score is usually close. Stanford is especially vulnerable this season playing without a FG kicker they trust.
South Carolina has only lost at home once in the past 3 years. Don't use Vandy as a guide. Carolina just hasn't played well vs Vandy in the Spurrier era, and has even lost twice to them in the last 10 years. Shockingly, neither of those two losses were when Vandy was at their best. Some teams just have a thorn they can't shake. Vandy has been Carolina's thorn under Spurrier. Oregon State has been SoCal's thorn. South Carolina is 2-0 in SEC games vs Mizzou. Look for that to continue with Carolina at home and Mizzou coming off a loss to Indiana (at home).