For the most part no, but I am sure there are plenty of circumstances where it could.
Trubisky may be a good example because throwing him out there as a rookie was not that detrimental. Throwing him out there as a rookie and then firing pretty much his entire coaching staff three months later was rather detrimental. I don't think Pace does that twice and we all now have to cross our fingers that Matt Nagy finally gets his shit together.
Andy Dalton's entire career has been a model for "average NFL QB" play...not complete shitshow with a weird neck. If Fields can play better than Dalton, he's ready to start...no matter when that is.
I have a bit of a different take on this. I think starting Mitch his rookie year actually was detrimental for him. The weapons were absolute dog shit and he did not have much experience entering the NFL. It would have been ideal to sit him and have him develop. Sure, he likely still would have sucked, but maybe not as bad. The problem was Glennon was so terrible, there was too much pressure from the outside to start the rookie QB that they just traded up one spot to get.
I also don't think firing Loggains and Fox ruined him either, and I certainly hope Pace doesn't look back at that as a mistake and a reason to keep Nagy around past this season if the offense still looks bad or underachieving. If Nagy is still Nagy at the end of the year, you fire him and fire him fast. There will be a lot of qualified coaches who would love to coach up Justin Fields. I personally believe Fields will do more to help Nagy than Nagy will do to help Fields. We could cross all our fingers and toes but Nagy is not going to get his shit together. We've all witnessed 3 years of horrendous decision after horrendous play call after undisciplined play on both sides of the ball, I have no idea why anyone would have any faith at all in him getting his shit together anytime soon.
The start/sit question is an easy one...you let them battle it out in camp and if Fields is clear cut and looks special, you start him. If it's close then you have bigger problems on your hands. Fields should definitely be noticeably better than Dalton.