Within reason, yes. There is a limit to how many people will buy fast track tickets, obviously they don't sell unless there are queues so finding a balance is key. Also if you sell too many its counterproductive as fast track is no quicker. If you only get on 3 rides in a whole day because the offering is poor you will start to lose visitors, and I think chessington is close to this.The cynic in me would suggest that low capacity = greater sales of fast track.
And possibly more return visits... if you can't do everything you want in a day, you'll have to come back!
Ideally you want there to be too much for a single day creating revisits or overnight stays, or the ability to pay for fast track to do everything in 1 day.
Personally I would say chessington is a 1 day park with poor capacity making it very unpleasant. My kids do love it though so we always end up staying over so it doesn't seem that much of a waste only getting on a few rides each day.