On a 355m Enterprise, the dorsal width is 22.5' or 6.858m. The torpedo bay is approx 47' across.
I did a size figure table yesterday, based on the Kimble blueprints and screencaps like
this one from TUC. On a 355m Enterprise the navigational deflector casing would have a diameter of 19.8 m and the (max. / bow) width of the torpedo bay would indeed be 14.3 m or 47'.
Nevertheless the dorsal would be wider than 22.5', according to the screencap its width is 59% of the torpedo bay width, thus 8.4 m or 27.7'.
The problem with your screencap is that the widest part of the torpedo bay isn't obvious from that angle as it is towards the front and tapers to the back. The dorsal will appear wider from the stern.
The only known low-distortion view of the Enterprise is the one from Drexfiles' orthos and the dorsal width is only 48% of the torpedobay and not 59%.
Where is your source for this? The Drexfiles ortho is from the CG TMP Enterprise that was accuratized Foundation Imaging for the TMP Director's Edition. Kimble's blueprints has it's own issues and I'm not using it.
Also, be careful with using
your screenshot as you need to account for perspective and camera distortion.
I'd like to think I pay attention and consider lens and perspective distortions. Since objects closer to our point of view appear larger than they are the TWOK screencap may be debatable.
However, that's different with the aforementioned screenshot from TUC where the max. dorsal width (visible) is
behind the navigational deflector and the forward edge of the torpedo bay.
Yes, but:
1. from that angle the dorsal is tapering already (top wider, bottom lower) and we can't ascertain how wide the bottom of the dorsal is when it connects to the torpedo bay,
2. and we can't tell the actual max width of the torpedo bay from that angle as the widest part isn't obvious as well.