Lancashire finished 21 points adrift of Nottinghamshire as they were relegated for a fourth time since winning the Championship in 2011.
They lost six games, including four by an innings and three of those in a row through August and early September, which left them too much to do in the final two matches.
Lancashire only managed to collect 15 batting bonus points all summer and no batter apart from captain Keaton Jennings averaged more than 40 runs.
Previous captain Dane Vilas left last year, while Steven Croft retired from red-ball cricket and that experience in the middle order was never replaced.
It was a very tough challenge for youngsters who were blooded, like 16-year-old Rocky Flintoff, son of former England captain Andrew.
“Division One has some very experienced teams,” said Benkenstein. “When you do lose a bit of experience in key areas, we’ve seen a big difference.
“It was also a tough year to get quality overseas players for long periods of time.
“We needed that to help balance the team and to not put as much emphasis on young players to win us games.”
