Normally the fine details would be some through something like a normalmap, which gives them the impression of being 3D when they are actually 2D. They also have access to stuff like shaders worth a damn, so you can make a hexagonal or even cubic model look perfectly round (if you look closely at the ends you'll usually be able to see this) by fiddling with the normals. TMT won't support anything remotely like this so we just have to get by. Even if it did support them it's unlikely it would have much of an impact on the rendering cost.
tl:dr learn to make models efficiently. You'd be surprised but you can usually cut the part count down by a hell of a lot while maintaining the detail. I think I could say something about having your cake and eating it but it's yet to come to me.