No. You're the second person guestimating the size of the nacelles to be much larger than they really are. The Galaxy class had nacelles that were about 1000 feet long, that's the size of a very large skyscraper or the length of the entire original Enterprise. Galaxy was HUGE, just the Bussard collector would take up half of this picture. The odd angle and perspective in this picture exaggerate the distance, but we don't have more than a couple hundred meters of length max in this picture if we use the men in the foreground and the far back as a comparison. That would be about right.