I was a landlord for the past 5 years before we moved halfway across the country in January. We required a years rental history and if that wasn’t there (as it may not be for college students) then we asked for a guarantor. Yes, all residents needed their own guarantor and all guarantors were responsible for the entire rent.
We never had to ask any guarantors for rent, they made sure that their student had the money to pay for it.
We did have a couple of parents refuse to be guarantor, we did not allow them to drop off after the first year lease was up. In that case we asked for a prepayment of 6 months rent, then another prepayment of 6 months rent, then they had their year rental history and could pay month to month.
One particular group of students whose parents would not co-sign had a hard time coming up with the 6 months rent. The parents also refused to give them money for that. So, they went and found a couple extra room mates (we allowed 2 per bedroom) and each room mate kicked in a months rent for the prepayment.
There are lots of ways to make it work.