Small cars are passable, but do not match the visual appeal of long cars and long trains gliding through gentle curves. Of course, on a large pike with tortuous, tight curves, long Heavyweights might not work so well. The Madison would be a better choice, and Classic - sized freights would work well. Large pikes demand longer trains, provided there are long straightaways and gentle curves. A freight train of twelve cars looks good, and twenty looks better.
Passenger liners can abide five to twelve cars easily.
Tightly-curved pikes with less straightaway can handle longer trains, yet will abide small consists well. Small pikes invariably have tight curves. Longer scale cars are at a disadvantage. The best picks are Classic and O27 sizes. Likewise, short trains are in order.