I still hold the opinion that the game would have been better off with a much simplified system, where the game determines how many power blocks you're allowed (or how many of your power blocks will be active) depending on how big your ship is, in terms of volume, and there is no need for any additional thinking.
Note that it wouldn't be the volume in terms of how many total blocks: it would be volume in terms of the volume the ship can contain (in other words, how easy it is to hit with gunfire). If its hard to make a computer figure out the volume with some kind of 3D volume determining algorithm(the ship could contain holes that would break such an algorithm), the game could look at your ship from every direction, paint a silhouette for each direction (13 total silhouettes, for each edge, corner and face of a cube divided by two), and determine your "volume" from the total surface area of each silhouette.