Are these three scholarships looked at by different committees? Also the first essay question is the same for Ervin and Rodriguez. So, can use the same essay for these two?
The are probably read by different committees.
And, yes, for the first question, it’s fine to use the same essay. In the second essay, you should tailor more towards the biographies of the two people in the two people in honor of whom the scholarships are awarded and how your background, interests and experiences reflect the goals of the programs in light of those biographies and the four pillars which reflect the goals the program and what they seek in their applicants.
Good luck!