I think it is a number of factors, and there have only been 2 CC games.
Chris Green added to the CC team is great for us.
Jennings losing the captaincy a few games before Benk left has led to his form improving.
The ball used is easier to score with the last 2 games.
Both CC games since Benk left have been at smaller club out-grounds, which if the wicket is okay can lead to higher scoring rates.
I don't think Benk was good for us, but everything else contributes and the problems are further up. The improvement is good to see though, and will need to win 4 out of 5 go up if there is no big CC restructure which was suggested a few months back.