Well, there is some difference between 318 and 1,500 students, but that is
unarguably too many for four non-Wikipedian CAs to handle. Too many for
four Wikipedians to have handled, too, for that matter.
I'm not sure I follow your logic on the grad student bit, though. Don't get
me wrong, being paid for my CA work would be great. However, paying grad
students to do the work? Unless you're specifically talking about finding
grad students who are also Wikipedians, it seems like you'll have the same
issue. Paid or not, they're still not Wikipedians. I don't think the
current issue with the CAs is that they don't have a monetary incentive to
do the work. They just aren't familiar enough with Wikipedia to know how to
handle some situations. Paying people who don't know Wikipedia will not
change this.