Cedar Creek Mine Ride had six blocks on it if I remember correctly, ending at the load station, top of first lift, block brake before long drop, top of second lift, brake before helix, brake after helix, and unload station. And it was run by hand.
Today, both mid-course brakes are completely gone so the ride has only four blocks and thus can only run three trains. And it's not run by hand anymore.
One thing that Cedar Point has learned is that their optimal dispatch interval is about 70 seconds. It doesn't matter how many trains you have, it takes a certain amount of time to get them loaded and unloaded, and if you can keep that time down to about 70 seconds, that will determine your capacity. Adding more trains only means you can make the ride longer. The only way they could use more trains would be to use dual stations as Disney does, and that adds complication to the ride that Cedar Point probably doesn't want to contend with.
--Dave Althoff, Jr.