I know someone who was pretty similar to me in terms of stats and ecs, but who was a year older than me. They applied to wharton even though most of their ecs were in science (they changed their mind about what they wanted to do in senior year) and they got deferred/rejected. I want to do science so I am applying to college of arts and science, would my chances of getting in be significantly higher, or not much difference?
Nobody can answer this question with any degree of certainty. It seems like you might be justifying that other student’s rejection by indicating that they didn’t have a history of demonstrated interest in Business and thus Wharton wasn’t buying their app-- but Penn isn’t a place that particularly cares if you’ve been able to do amazing things in business, science, history, math, etc.- they want to see passion, interest, and curiosity in its raw form so that you can develop it at Penn, no matter what you’ve done in the past. And they also want to see a good set of reasons why you want to study what you profess to enjoy studying. But business intersects with a lot of areas of study and so not participating in the Future Business Leaders of America won’t hurt a Wharton app any more than it would hurt an app to Engineering. Had your friend been able to convey that interest, no matter his non-business background, he likely would have been able to get into Wharton assuming he had good grades, good SAT scores, and more luck than the 90% of students rejected from Penn each year with good grades, good SAT scores and good reasons for their intended course of study. Admissions in this day and age for students with the right credentials truly comes down to luck. So perhaps your chances are better because you can write a more compelling essay about why you’re interested in your intended course of study or maybe your GPA is slightly higher or maybe the admissions officer is just feeling a little bit perkier the day they read your app— it’s honestly impossible to know-- so you just have to take that leap of faith and hope it works out!
Good luck-- happy to answer any questions about Penn you might have outside of your chances of getting in 
No one can really answer that. Most would hypothesize that your chances are slightly higher in the college, but it the difference is not big at all. The best strategy imo is to apply to the school best signed with your academic and/or career interests at this point.
Thanks!!!