King Daniel wrote:
Time to send some technicallyminded fans' bloodpressure through the roof.

By the way, I did a quick pixel measure on the lightened image from page 10 of this thread. If the middle "jar" structure contains the bridge (seems like it has the same lights as the set pictures), that measures about 100 px. The entire primary hull is 1800 px across, or 18 times as wide. So, if you put the bridge at, say, a liberal 20m diameter, the hull is 360m across.
Anyway, if Vengeance "twice as big" as the Enterprise, that would downscale the ship to about the size of the TMP refit (in fact, your diagram above shows the length of the Enterprise is roughly the same as Vengeance's saucer).
BUT, if you look at the scene where Vengeance is crushing Alcatraz, the "death ball" is roughly the size of the lighthouse, which is 27m tall. I measure the starboard one to be about 65 or 70 px, which suggests about 0.4m/px. So, an 1800px diameter would be just under 900m. But that would make that central structure almost 50m wide.
Looks like the graphic artists are taking liberties again...