I think Colombista is referring to the main piers, which are much larger than the piers which attach at the points of the weapons sails. However I think that foreshortening and perspective is distorting it: GP hasn't actually modelled the main piers yet. There is a 120 degree difference between each connecting pier, so that means that the alternate piers are missing so far!
All in good time I am sure. Good luck on this GP, looks splendid, and I think I could park my station inside yours hahaha