First, you're mixing up MSDs of thoroughly-designed ships with those of haphazard designs. The reason MSDs of the Galaxy-class and the Intrepid-class are more consistent is that their artists had Andrew Probert's and Rick Sternbach's respective information to work with. Doug Drexler's (once again, not Mike Okuda's) MSD was drawn up based on no such information, as if it were a ship of the week.
Second, the external design doesn't contradict the MSD, because you have no proof that those are windows. You have a reasonable hypothesis, but no proof. Also, I'm not sure what you mean by unrestrained conjecture - the 170m figure would be consistent with about two decks in those "window" areas, and the model had been built long before the MSD was drawn up. The MSD would be 120m long or so.
And no, we cannot abandon the MSD, because it's onscreen. A lot. I rewatched seasons 3-7 and it appears over and over and over and over again, with many instances of closeups where I can count four decks and see the layout. Compared to that, the references to Deck 5 appear in three episodes, the text on the turbolift schematic is invisible, the VFX is all over the place. The MSD isn't gospel if there are clear inconsistencies and needed additions, but its core layout should be maintained in order to avoid contradicting the overall experience of the show.
Second, the external design doesn't contradict the MSD, because you have no proof that those are windows. You have a reasonable hypothesis, but no proof. Also, I'm not sure what you mean by unrestrained conjecture - the 170m figure would be consistent with about two decks in those "window" areas, and the model had been built long before the MSD was drawn up. The MSD would be 120m long or so.
And no, we cannot abandon the MSD, because it's onscreen. A lot. I rewatched seasons 3-7 and it appears over and over and over and over again, with many instances of closeups where I can count four decks and see the layout. Compared to that, the references to Deck 5 appear in three episodes, the text on the turbolift schematic is invisible, the VFX is all over the place. The MSD isn't gospel if there are clear inconsistencies and needed additions, but its core layout should be maintained in order to avoid contradicting the overall experience of the show.