The chances of getting one of those merit scholarships is very small. They are given to remarkable students even among the stellar crowd.
I heartily encourage any and all students applying to these colleges to apply for these merit awards if any separate application is required. Some of these schools automatically consider all applicants for these awards, some require a complex process, including high school involvement such as nominating the student for the awards. But go for it! Why not? It’s no different than those who need financial aid to go to a school but have unusual family financial situations that involve some chance in getting enough awards to make it work. Chance is a big element in all of this.
So if there are schools out there with sufficient merit money that make it possible for your family to send your student to them, go for the awards if that student wants a chance at those schools. OP has indicated son has an excellent safety option that is affordable, so no reason not to reach for the stars and for as many options possible.
It’s problematic when kids or parents don’t get it that the accept rates at the very top schools, certain programs, merit money are lottery tickets and they obsess about these things so that they are so invested in getting that outcome that they neglect to cover their bases in terms of realistic applications as well. As long as a student has that covered, go right on ahead and see what can pan out.