Sgu vs ross are basically equally bad choices. Both have an extremely high fail out rate and skewed published statistics. Take a gap year, buff your low points on your application and apply DO.
If your set on carib....
I believe from my personal experience that SGU might have a higher fail rate, but seems to have more name recognition. They matched about the same amount of grads last year, sgu matching about 30 more, but we do not know what the starting classes were. My starting year at SGU had about 1250 in it...and only 800 ish matched. Keep in mind many of those finished in more than 4 years.
Also, stating SGU is the "top Carib school" is a ridiculous statement. It is the best of the worst options out there. You wouldn't say you were the best of the bottom tenth of your class would you?