As you said, ships tend to clump together, but it has occured to me that this may be related to lack of shield meshes for most ships. I think I remember you saying that fighters were flying through the ships because of this, and it seems possible that formation spacing is also determined by the location shields. If this is the case, than the spacing issue should solve itself when you get the shield meshes right. I hope this idea helps/has any merit whatsoever.