"[Some] NCAA I sports are Head Count sports: Men’s & Women’s Basketball, FBS Football, Women’s Gymnastics, Tennis & Volleyball. A head count sport means the stated scholarship limit is absolute, and the number of athletes receiving awards cannot exceed this number, even if the awards are partial. Head count sports generally award a much higher percentage of full scholarships than equivalency sports.

"Why are some scholarship limits fractions? All other NCAA sports are Equivalency Sports which means awards can be split into partial scholarships in any proportion up to the maximum allowed. For example, an NCAA Division I school could award 24 Softball players each a 1/2 equivalent scholarship and not exceed the limit of 12 per team. Full scholarships are relatively rare in equivalency sports compared to Head Count sports."

So looks like Basketball, FBS Football, Women’s Gymnastics, Tennis & Volleyball are headcount but others can offer partials however makes sense.