I think it wouldn't have been bad out of hand for Bagent to start in week 1. Make rookies earn their reps, no qualms here. But right now, looking into week 4, these are the most valuable reps you can give to Williams and I don't value looking in the rearview mirror. These are the most competitive defenses he's had to play against, and the short time to make a good decision is crucial. Right now, this is valuable experience to grow from (NFL players seem to me to be the type to learn from doing). We are in "IF" territory. IF Williams was worth the pick invested in him, these are important lessons to learn from live fire. IF Williams was not, then we find out over the next two or three years, but his chances are maximized by investing these reps in him.
The difference between a strike at 40 yards and an ugly 5 yard overthrow is seriously 5 mph (presuming the difference between 45 MPH and 50 MPH at 6 ft tall, and a launch angle of 25 degrees and a flight time of 2 sec). That takes live fire to develop - practice doesn't cut it to me, given that practice is softer than in the day.
In the end though... did you have fun seeing any of the throws Williams DID make on Sunday? We got to see some big plays with some real zip