The discussion about high-poly interpretations of a low-poly mesh reminded me of Metal Gear Solid.
I recall reading in an interview that Metal Gear Rex was designed with flat sides, because that's all the Playstation could handle. Thus, it looked like this.

Rex makes a reappearance in Metal Gear Solid 4, with all the Playstation 3 horsepower that goes with it. Even though they could have made the legs cylindrical, with a hundred sides, they didn't;
the original design was flat. Naturally they added in greebles, bevelled the edges and the like, but it's still a very flat design.

What Konami did with Metal Gear Rex can be seen as the perfect example of what the FSU is trying to achieve. It embodies the act of converting a low-poly model to a high-poly model.
Notice that on the radome (dish on the left arm) they smoothed it over a great deal, because it was obvious that the intent was for it to look rounded. Also notice how the hydraulic spikes on the feet are rounded for the same reason.
You can take from this what you will, but on the subject of hexagonal missile tubes, I would vote for rounding them out; or, as this is a Shivan craft, make them edgier. But there's no need to chain yourself to 6 sides.