Sorry, which history is that?
I think history will tell you that Larry Brown plays the players who give his team the best chance to win, regardless of their age. Tayshaun Prince is a great example of a young player whose minutes jumped from 10 per game to 30 per game in his first year under Brown and second season in the league (the Ariza comparisons are inevitable). Eric Snow was an unproven 3rd year player when his minutes jumped from 4 in Seattle to 18 in Philly in a mid season deal and 35 in his first full season under Brown. Theo Ratliff also came to Philly in his third year and Aaron McKie in his fourth, so Sweetney, entering his third year, could easily thrive under Brown if he's in shape.
Larry Hughes came into the league pretty raw after only one year in college and he got 20 mpg under Brown. Tim Thomas, also after only one year in college, played 23 mpg and scored 11 ppg in one full season under Brown, his numbers are not much better 7 years later. Some coaches don't let 19 and 20 year olds any where near their ratations. So if Frye is half as good as Isiah thinks he shouldn't have a problem after four years at Zona (problem is that Isiah thinks he's a #1 overall pick when he was barely a first rounder till after his senior season).
Nate Rob, who I know no one doubts, can be compared to Speedy Claxton, who played 22 minutes as a rookie in Philly. Although I would also love to see him come in a smother the oppossing PG the way Hunter did in the playoffs this year.
The young guys who he's sat are raw guys who were clearly not NBA ready like Darko or Dalembert or just plain old bad like John Salmons.