Hey Qaragan,
No, not a typo and no, not 'balanced'!
The idea is to approach High Guard (and the Core book, and the Vehicle Handbook, for that matter) as a 'toolkit', and remember that just because you can do something, it does not necessarily follow that you should.
High Guard (and Traveller overall) needs to be able to handle all science-fiction universes, not just that of the Third Imperium, so we provide as many options as we can. Not all options will work in all campaigns, and the referee should use his judgement as to what to employ rather than adopt a kitchen sink approach.
As an example, I am sure you and many others here could design a capital ship that could absolutely trash the Third Imperium warships in High Guard - they are not flawed, but instead representative of how ships in the Third Imperium universe are built.
With regards to hull types, the referee can choose to employ one or another depending on the end result he is after. He may, perhaps, choose to use one hull type for the majority of ships in his universe, and employ a more efficient one to represent a better ship yard without an increase in TL - it is just another option.
What High Guard and the Vehicle Handbook are not, however, tools to be given to players with no restrictions because someone at your table will min/max everything and produce a truly hideous warship. Remember, this is an RPG not a competitive miniatures game, and as we provide more options, the referee must exercise at least a measure of constraint.
Hope that helps!