@clk_mike Well I can see 2 problems in your statement. 1). 8 to 10 wagons are not big enough. This is what I consider a nice train: https://www.youtube.com/watch?v=OfmRaVYOsuI
And 2 years to reach 200 is way too much. Most of the time 2 years in debt can ruin your company finance forever.
There should be a way to decrease the expected frequency. I mean, a train pick up coal once a year is not realistic, but at the same time the train travels on real time. So basically mining should have no frequency limit. If I pick up once every 10 years is good enough. Because time is completely useless in the game.