I have no doubt that they Snead/Fisher/Boras/Weinke all thought they could get JG ready to be the starter at some point during the first quarter of the season or so.
When they scouted/interviewed and traded up to get JG, surely they were quite hopeful and believed JG would prove himself and win the job because of his talent along with the teaching of their coaching staff.
The second they turned in the draft card with JG's name on it, I believe they all thought it would come together less than 8 games into the season.
I also believe Fisher thought if for some reason JG wasn't capable of taking on the responsibility when they likely expected, he always had plan A/2 to ride it out with Keenum for a month or so had they miscalculated, which they probably did but they will never admit it.
Both JG and Fisher's offensive staff failed to deliver.. At this point I could care less who's more to blame. My gut tells me Goff was definitely more to blame in the beginning months but Fisher's staff after 7 games has to be held accountable for what ever reasons they're not going to admit.
Fisher has played this safe from the beginning of training camp. He's been safe to protect the psych of his golden arm from failure as well as the reputation of his offensive staff being qualified to groom a young spread formation rookie quarterback.