I’ve posted this link before, but it’s a very informative one, so here goes again:
https://community.bus.emory.edu/program/PreBBA/Shared%20Documents/BBA%20Admission%20Guidelines%20Spring%202016.pdf
The bottom line is that if you do well in your courses, esp the business pre-reqs, and as noted in the prior note contribute somehow to campus life you’ll get in. The required GPA is very do-able. I think that you even have an advantage at Oxford, in that getting a good LOR from a professor will be easier given the smaller class size.
I can’t compare the two schools, but you shouldn’t let admission to Goizueta worry you when you’re making the decision.