No. 4 - Seattle could draft Michael Penix, Jr.
There is no telling where Penix will go in the NFL draft. He has the arm talent to be a top-ten pick. He also had an injury history while playing at the University of Indiana before he transferred to the University of Washington a couple of years ago. While he was fantastic with the Huskies, he also had an excellent group of receivers and the best pass-blocking offensive line in college. Penix was good, but his team likely made him better and that would not be the same case in the NFL.
Besides his injury history, there are a couple of other reasons Penix could draft in the draft. One is that he does not appear to have high-level athleticism. At Washington, Penix could pick up yards at times scrambling, but against the speed of NFL defenses, he might not be able to do the same. In today's NFL, a quarterback cannot simply have a great arm; they need to be able to move around well, too.
Penix also is not young for a draft pick. He will turn 24 in May. This might not seem like such a big deal to regular human beings, but being a year or three older than other potentially top-end quarterbacks means a team might get a couple of years less from Penix in the long run.
But Penix has two huge things in his favor. One is that he has that electric arm. The other is that Seattle might hire Ryan Grubb as their new offensive coordinator. Grubb was Penix's OC at Washington. That would make the transition to the NFL easier for both Grubb and Penix.