Sure. But if an outside the top 30 freshman PG earns the starting spot in the era of COVID 5th years, the likelihood is that your team isn't in a great spot and likely mismanaged the offseason (or as happens occasionally the recruiting analysts were way off). That's my point.
Also that people need to manage their expectations about how good Nowell will be in year 1. Castle was a top 10 guy with NBA draft projections before the season. Here are the PGs/CGs in Nowell's range (composite 30s) last 2 seasons:
Jeremy Fears - Got hurt, but before that was backing up an average upperclassman.
Simeon Wilcher - Barely got minutes on a bubble team.
Layden Blocker - Barely played on a bad Arkansas team.
Garwey Dual - Had draft buzz, and ended up just a rotation guy on a mediocre Providence team even despite injuries.
Taison Chatman - Barely played on a mediocre Ohio State team.
Dedan Thomas - Started at the mid-major level for a mediocre UNLV team, but was overall pretty good.
Miro Little - Barely played for a good Baylor team.
Skyy Clark - Started out of the gate for an Illinois team, wasn't especially good, quit the team halfway through.
Collin Chandler - Went on a Mormon mission.
Seth Trimble - Played less than 10 mpg for struggling under expectations Carolina team.
Freddy Dillone - Redshirted, then barely played as a freshman this year.
Dior Johnson - Arrested and played JuCo.
Not a single one was a high major full season starter. Reed Sheppard was in the 40s, so I'm not ruling out Nowell coming in and being awesome. It could happen. It's just not likely. That and as pointed out in a couple posts before mine, Diarra was pretty good last season. I doubt Nowell could beat him out, and if he does, it's more likely that Diarra's shooting really regressed or something. But if Diarra leaves, we should absolutely look to get an experienced guard to start over Nowell.