Wikipedia says that 16 of Washington's last 18 starting QBs made the NFL, but I don't think that's right.
The source given for that stat is
this Wikipedia page. This page shows that since 1975, 15 of the last 17 UW quarterbacks made the NFL -- not 16 of 18. This page lists Keith Price and Isaiah Stanback in the NFL, but Price was cut in training camp and never made an NFL roster or practice squad, and Stanback played WR in the NFL. So the truth is that UW has put 13 QBs in the NFL since 1975. And it's interesting that only one of the last five UW starting QBs played QB in the NFL (Locker).
Pro Football Reference lists 14 Stanford QBs since 1970 who made the NFL -- Luck, Edwards, Fasani, Husak, Hutchinson, Stenstrom, Elway, Laufenberg, Schonert, Dils, Benjamin, Boryla, Plunkett, and Freitas. (Two of them went to Stanford and then transferred elsewhere, Laufenberg and Freitas.) That doesn't count 3 Stanford QBs who signed NFL contracts but didn't do enough to get listed in Pro Football Reference (Butterfield, Paye, Cordova). Nor does it count Scott Frost, who transferred and made the NFL as a DB.
So just based on sheer numbers, I think Stanford's quarterback record is comparable to UW's. And the quality of Stanford's "top 5" is much better, beyond dispute.