not so sure about a disservice. if one is median at either schools, chances for anything other than doc review may be slim, at least you won't be in debt if you goto cumberland. but you already have connections, so this may not even be a problem. sure, if you are top 15% at either school, job prospects will be better at UF, but again, you will still be able to find your first job at cumberland, and have no debt.
also while going to cumberland will not guarantee you a spot in the top of the class, you can reasonably believe that you have a good shot to be a top student, or at least the admissions staff believes so. and maybe cumberland has too many unqualified graduates, which is why their bar pass rate is low. but again, you have afull ride, so you should not be one of them.
T3's and T4's definitely do have a bad rep in certain circles. but the one circle where they don't have a bad rep is in the eyes of their alumni. there are plenty of successful lawyers from t3's and t4's, and if they see a good candidate from their alma mater, they are not going to think not to hire you because your school is shit. they want to enforce that they went to a good school, thus will give a very good look to solid students from their school.
if you are set on biglaw or a job that requires being a top student from a school with some prestige, don't goto cumberland. but if all you want is a solid job, no debt to provide you with versatility in terms of the the job you can choose, the decision you make is an equal tossup.