Your profile seems good, it looks like you're working on the things that you need the most, like your work as RA.
You didn't tell whether you will apply to Quantitative Marketing or Consumer Behavior, but from your profile I guess Quantitative Marketing. Since you have been working in analytics, I'm also guessing that you know how to code.
20 is high number of applications, but that's the number of programs I applied to.
Every time I see a list of school like yours (Wharton, Harvard, Columbia, Stanford, University of Chicago) I get the feeling that the person didn't do a good job at selecting schools yet. When people are good at selecting schools, usually the list looks very different. Because a good list is based on the programs that are the best fit, and not the programs that are better ranked.
Just as an example, oftentimes if Harvard is a very good fit, then Stanford isn't. Their research interests don't overlap that much (I may be wrong, it's been a long time since I compared schools), so it would not be common to see both of them being a very good fit for the same person. I think that Harvard and the University of Chicago are also very different from each other, with Harvard being closer to managerial and strategic topics, and Chicago being closer to economics.
On the other hand, you may have a school that is not usually a "top school," but for your specific research interests it is a top 5 in the world. Different universities can focus on very different types of research.
Some top researchers can actually prefer lower ranked schools, because they can stand out more, and get more resources and control over the research they do. Just to use Harvard as an example, I met a professor who left Harvard and another professor who refused offers from Harvard because of that.
And I really don't know if there is such a thing as safety school for marketing PhD. If you are a strong candidate and apply to a program that is quite lower than expected, there is a good chance that the program will not even consider you application because it know you will probably get a better offer from another university.
Make a list of school that are the best fit for you, especially taking into consideration research fit, regardless of the rank. Of course you don't need to go as low as top 300, but among the top 100 you should be able to find 20 schools that are a very good fit in different rank ranges.
You can still include some dream schools, even the fit is not good, you never know what can happen. But don't focus on that, dreams can become a nightmare if the fit is not good.
Competition for marketing PhD programs can be fierce, probably anything in the top 20 is very hard to predict even for the strongest applicants. Don't focus too much on the top ones.