For you rail fans out there, here's one for you; without the obvious disadvantage of turn radius, which would make a better steamer, an articulated locomotive (like the UP 3900 Challenger), or a Duplex Drive locomotive (I don't know any examples)? So, before an argument, let's recap what those are; an articulated locomotive basically seperates the boiler from the drivers, leaving them to be able to bend, like a bogie (or a truck, as you Americans call 'em). It has an obvious advantage at turn radius, but, my theoretical disadvantage is that it would be hard to get high-pressure steam from the boiler to the moving cylinders, because you would need a flexible pipe, which can't hold too much pressure before exploding. A Duplex Drive locomotive is basically a rigid-framed counterpart tothe articuleted, with the same four cylinders. It really hates tight turns, but, with two cylinders powering one connecting rod, and, therefore, one set of drivers, it may have more torque. Think of it like a 4-8-8-4 competing with a 4-16-4 Duplex on a straight track. Which would win in terms of acceleration, top speed, traction, and torque?
P.S, It is a straight track, with no turns.

In my opinion, I would say the Duplex would win in torque and speed, but, with more weight behind it, the articulated would win in traction and acceleration. Wow, I just realized that I had never even said "train" once in that paragraph.
P.S, No sanders allowed, no gradients, and both locomotives are simple, high-pressure locomotives, not compound.