The belly has the hangar hole. And hte bridge officer would have no way to watch the combat. Not one military or civilian ship in use right now puts the navigation bridge into the ship, where there is no way to look outside.
Nope, in the Distant PAST of Star Wars, nobody read or watched Enders Game. Because it did not exist yet.
So that tanks have the strongest armor in the front and turret, the weakest at the bottom, top and and is just a "silly design"?
Or could it be that decades of tank warfare and warfare preparations have reavealed that to be the most ideal armor placement for open warfare?
So the design is bad against IED's and mines? Well, duh! It was never designed to counter those.
We need to make a new design that is better suited for that. What, that design sucks for open warfare? Well, duh again! Same reason, different direction.
Every tank, every helicopter, every ship and every soldiers bodyarmor is designed by the same principles:
Strongst defenses in the direction you are facting the enemy fire from. Wich will likely be the direction you will fire towards too. Ideally that should be one direction - the front.
Because armoring both sides as heavy just ends up doubling the weight and material for the same protection.
You beat me to what I was going to mention, that design isn't solely about where things are wanted/ought to be.
Ship design in this regard, would factor in materials and efficiency as well, unlike in the video game world where resources are near infinite, reality isn't like that. And to use as few resources to achieve maximum effectiveness be the goal.
Be that full 360 degree coverage of weapons(would place and design their mounts in a way to use the fewest possible to achieve this) or the more plausible outcome, ships specialized for roles, as to make efficient use of energy generation and fuel on board. Ships designed akin to destroyers to swat out fighters and bombers, maybe dedicated anti missile ships, dedicated missile ships themselves (because let's be real, missiles are probably the most accurate space weapon that we as humans would use, we have targeting and guidance down to a science itself, we just have to make em space borne and increase yields) dedicated carriers and gunships as well.
Not saying there wouldn't be a capital ship that's capable of many of these roles on their own, just in terms of marterial usage, this is how you getaximized results with minimal material, Highly specialized ships, which is the continuation of your point on tank armor, but in space.
There is left out fleet tenders, and tankers that keep ships remotely Susie's, because space is big ya know... and adding habitat stuff would make a military vessel all that less efficient, so ships that are solely designed to grow food/process waste, make water in space, process and store fuel, ammunition/batteries/whatever else would be needed, are also a concern.