in order to understand star ship design realities, take your popular star ship whomever it belongs to and turn it upside down; if the ship looks the same upside down as it does upside right, your design makes sense to all the physical laws as we know them. If it doesn't, your star ship design is nonsense and wouldn't work in space.
Hence, the only true star ship design is a ball (deathstar). All the ships with "wings" (X-fighter) are nonsensical.
Even disc-shaped UFOs and Billy Meier's "Beam" ship photographs strain credibility: Why advanced aliens visiting our planet would have ships with a "top" or "bottom" is thus beyond my imagination, yet I believe they are real and have been visiting us since the beginning of Earth's time (and taking samples e.g. I'd like to see their Dinosaur zoo).
All the problems with Star Trek etc. have the ships moving in the direction opposite where their engines are located; pushing it "forward." e.g the engines are at the back. In truth, the engines wouldn't be "at the back" because there would be no "back" that is, no aft, bow, stern etc.
Warp Drive and "warping space time" has nothing to do with engine shape or position in a structure. In truth, there would be no visible structure attached to a ship that would even remotely look like an "engine." This is why UFOs might have bubbles on the bottom performing some function, but their timedrives are no where to be seen attached to the outside of their "ships."
Warp drive "chambers" produce a "field" around a ship, enveloping it, and the ship doesn't move or "travel" anywhere; it simply disappears from existence in space/time and re-appears in another location.
Only the entities (The Navigators) in Herbert's "Dune" came close to explaining how warp/time drives would keep you from materializing inside a star or planetoid: You would have to have the ability of seeing the "future" in order to relocate your craft after you have surrounded yourself in the warp "bubble."