KCC got stale last year under Reid, it was when Nagy took over the playcalling that things got revved back up.
Regardless, it's not surprising that it takes more than 4 games for a young QB, new HC, and new OC to get things synched up. Perhaps they never do, but this is way, way too early to be giving up on it. The payout is too big if it hits.
Regarding the original topic, I prefer Rosen's talent but would take Trubisky if I had to choose between the two. One of my dynasty rules is to get young QB with offensive minded HC's. Those guys, if successful, will never lose their (real) OC and never had to learn a new system. Look at the big boys - Rodgers, Brees, Manning, and Brady being the exception where his OC has been around forever. The problem with stud QB's under defensive HC is that if their OC does really well, he gets a new job and the QB is likely going to have to learn a new system. This is why I am banking guys like Wentz, Carr, and Trubisky, there's a lot more potential long term continuity there.