Watched Attack on Titan Season 3 part 2? Then you can maybe look at this.

There is a meme among Attack on Titan fans about Isayama not giving Reiner the sweet release of death.

The guy has so far been blown up, stabbed in the neck with a sword, and blown up again. So, why didn't he die? Well, one of his abilities allows him to migrate his "brain" to different parts of his spine, and since you have to destroy the brain of a shifter to kill them, that's kind of a problem.

I wanted to give my dragons something similar. Generally speaking, "small" (read: shire-horse-sized) dragons can still be a TPK (Total Party Kill/wipe) for a band of medieval adventurers, but things quickly shift around once guns start to appear.

With their low/non-existent population growth, dragons simply lack the means of countering humans. Though they have the Foundation on their side, I still wanted to give something to help them remain formidable. They're team players, of course, so then let's think up something to make dragons better at it, especially since they were genetically engineered to be useful for modern combat.

Dragons: Large Mesh, Small Hitbox

The basic "design principle" behind my dragons is that all their vital organs are concentrated into small "box", their chest. This box is already surrounded by a large cage of bone, to which the flight muscles are anchored, giving it two thick layers. After that are the larger chest plates, with a microstructure reminiscent of abalone shells, and the Foundation-issued body armor. Most animals are already built similar to what I describe, but one key organ was still missing.

This is where their spine would come in. With multiple "knots" in it, that serve as real-time backups of the brain, believed to originally have been an adaptation to synchronize flight muscles better. One of these backups is, of course, inside their chest.

These adaptations are supposed to make going on "grizzly bear rampages" safer, though the intense parts of those only last for a few seconds, after which the dragon would collapse from wounds and exhaustion, usually at a safe spot. Oh, did I mention this "grizzly" also had an automatized grenade launcher strapped to their back, so those seconds will go like "BAM! BAM! BAM! YOU'RE DEAD!" for hostiles.

The Foundation has advanced medical technology and dragons can perfectly regenerate lost tissue (as long as their body knows how to), so they can patch up injured operatives nicely.

But how could such a redundant spine work and be good at its job (keeping the dragon's memories intact and heart beating)?

Note that simply looking at evolution doesn't always help, as evolution is more like a "whatever works" guy, rather than a cold, conscious, calculating engineer.