^Then what happens if 2 Polaris class ships need to dock?
No, a docking mechanism should be androgynous to the ship for maximum utility.
Hmmm, this might not sound related, but when the ship lands, how do people get to the ground? is there a rear elevator that drops down?
Vektor, re: your structural concerns. Remember this is future technology, I am sure metallurgy has advanced enough that telescoping structures should provide enough tensile strength for these purposes. Unless your planning high powered maneuvers while docked?
Based on the known details of the ship internals/functions, the design I showed is probably the only way to go without adding/changing external structures.
If your open to additional (somewhat large )structures I can think of several neat ideas.