Quick question to the BFG gurus: since, as far as I understand, the difference between most ships in the same class (i.e. cruisers, which I'm led to believe is the "important" class, comprising the backbone of a fleet) lies in the armament, mounting magnets on the ships' hulls and weapons would allow for the building of a "configurable" fleet, i.e. one in which you could swap classes as you see fit.
Is this feasible or does the plastic pieces' configuration make this impossible?
I'm starting to get ideas, here...
Only this: yup, yoiu are on the right track here!