One thing you gotta consider in this equation is supply & demand. There's a ton of teams that either need QB or could use an upgrade on their roster. So even though I think Nix is a third to fourth round type will he really last that long. I'm not so sure about that. He might go off the board round 2 which would not be "sliding" to me, rather it would be him going a bit earlier than he should due to demand.
Also McCarthy... I pray he goes off the board before 19. More QBs that go off the better as it pushes down impact players at key positions where we have very strong needs.
I'm a bit higher on Penix than most. But it would not surprise me if he went round 1.
Williams, Maye, & Daniels probably all go off the board for sure prior to 19. After them you have some guys who might also sneak into that first half of round 1 group too. Word is teams are high on McCarthy which is great for us. Penix is certainly (IMO) possible if his medical stuff checks out. Pratt is a potential climber for a couple reasons, those being his Senior Bowl week workouts plus he's got a strong arm so he'll wow in his workout I am sure.
I'm hoping we see a run on QBs prior to 19 with a couple reaches made. Then we get a fucking stud like Latu or one of these other guys who otherwise would be unlikely to go off the board that low.