Trey Lance only played 4 games where he got double digit attempts.
His QB rating was 110+ in two and 50+ in two. His YPA for the wins was 10+. He also ran a lot and got significant yardage.
He has played very well and very poorly.
Maybe they can train him up. But even as is, I'll take 50% chance of good starter play out of a backup.
Running QBs are ideal as backups, IMO. A running QB is a significant add to the offense. The downside is long term injury risk. But I'll take the add for higher production out of the backup and not care about long term injury risk for a backup.
It's 50-50 whether the poor games or the good games were the aberration, and those odds should only improve as he gets more experience. I'm not penciling Lance in becoming a good starter, but there's a good chance he'll get there someday, particularly if he can stick with a team for a few years. Sticking with the team for years is how Cooper became a competent backup, IMO. It wasn't arm talent or foot speed.
Back to Lance, he's a decent backup already based on his record, and has upside to a starter.
Signing Lance was a very good risk/reward move by our GM.