Are you still going to use the leader screen with the thumbs up? I feel like you should change it, as it makes it feel more like a joke civ.
Also, I'd say you should change something about the UU. If it can only move on railroads, it'll be a huge handicap to the civ's offensive capacities, as in 99% of the cases they wouldn't be able to move them to foreign lands. Of course, you could use it as a defensive unit, but anyone trying to wage an offensive war during the time they're available would face huge difficulties. The two solutions I can see are either trying to find a way of moving it by land, during which it'd be unnable to attack or defend, or making the normal artillery still available to build.