isn't it better to take away a few scholarships and spread them out to add depth to your roster?

Depth is key, perhaps adding 10 guys on partial scholarship is better than having 5 full time guys. Especially at this level, where the full scholarship player isnt all that much better than the partial guy. A lot of FCS schools have talented walk-on guys too, happens to UNH all the time (Andy Vailas).

A team could have a roster of 63 guys on full scholarship
A team could have a roster of 58 full scholarship and 10 partial scholarship, adding depth to a few key areas.

perhaps offering those partials to players that would be talented walk-ons at other schools too.