All Sims recruit in two pushes: the first is for N-2 recruits prior to the start of recruiting (where N is the number of open scholarships).  Thus if a SIM has 2 or less openings they won't do any initial recruiting.

They will spend a large portion of their money in the first push and they get an advantage in that their costs for Home Visits are around 200 miles (keep that in mind if you decide to battle a SIM who seems to be far away from the recruit and you mistakenly think you have a huge distance advantage).  Prior to the start of signings, SIMs will not put in any further effort until after signings have begun (thus if you've taken the lead on a SIM then they'll likely sign with you unless someone else intervenes).

After signings have started, the SIMs will do another round of recruiting to try and fill in all their remaining openings that haven't been filled yet (which may be up to N again if all their initial recruits are contested or taken away) with the remainder of their cash.