Bill I'll ask you directly this question, you know how the Vengeance is "officially" about 1500 meters? I'll add the second part when you respond.
Actually, AFAIK we've only estimated Vengeance's length based on its size relative to the Enterprise; it appears to be just about twice as long, which would put it at 1400 meters long.
Incidentally, 1400 meters is about normal range for a sci-fi warship these days; SDF-1 was 1250 while Battle 7 came in at 1500.The battle cruiser UNSC Pillar of Autumn
was 1170 meters (although none of the single-player levels in Halo-CE would actually fit inside it) and its counterpart the Truth and Reconcilliation
is about 1700 meters long. The (reboot) Galactica comes in at 1440 meters while the larger Pegasus measures just over 2000 meters. What's also telling is that every one of those ships have "little brother" counterparts that are depicted as something less than full-sized battleships; most of those are in the 500 to 800 meter range. Forward Unto Dawn is the smallest, measuring 450 meters in length, while Battlestar Valkyrie gets about 850 meters from stem to stern.
All in all, Vengenace is a pretty normal-looking starship where contemporary science fiction is concerned. There may be a possible scaling issue with some features being too large and others being too small; that, too, is actually pretty normal.