Realistically the niners need a QB who can hand the ball off and get quick passes into the flat and a few yards down field reliably. That’s your go, Deebo, Ayuik and McCaffrey do their work from there.
Your D is still very good, the problem will come in Jan when you come across very good D’s but also with very good O’s. Then it’s can you score enough and also keep their O off the field. Newton and Mayfield both can do this and I’d be surprised if either don’t get a work out.