Teams going thin at backup quarterback with their starter firmly in mind is not uncommon in the NFL.
Until the drafting of Jordan Love, the Green Bay Packers had the likes of Brett Hundley, Matt Flynn, Seneca Wallace, and Scott Tolzein take snaps in place of Aaron Rodgers. The Indianapolis Colts famously had Jim Sorgi and Curtis Painter backing up Peyton Manning because their season was lost anyway if their starting quarterback went down.
The Houston Texans are going thin at quarterback in 2022 all the while second-year Davis Mills is still an unproven commodity.