We’d usually keep brainstorming for other phrases in a situation like this. An easy decision to make, an obvious choice, an easy choice, etc. My kids learned the value of a thesaurus in writing during middle school, and sometimes I encouraged them to Google for synonyms while working on their essay. They would do it for school assignments, sonehy not this?
In my opinion, they should edit and polish their essays as they would any other piece of writing. “Their voice” doesn’t preclude thinking about what works best for their audience and serves their goal of getting admitted.