Actually, the Fallen are nearly impossible in real life. To accommodate a second set of arms, their skeleton would be much larger. Think of having a second set of clavicles, ribs, etc. Then there is the issue of center of gravity, I think unless they were hunched over a little bit, you could just knock them over. They could exist in low gravity, maybe.... Then again, maybe that is all they are used to.

The design of their Ketches is also pretty absurd. That massive offset engine would be almost impossible to stabilize with the smaller engines around it...

I disagree on that part. In space, your craft shape does not matter much, only mass distribution. I think they could totally build that ship design. What I don't get is how everyone teleports out of their ship.... Actually, for that matter.. Why don't guardian ships have weapons? I'm sick of fighting the archon priest, nuke that thing.

In space, sure. But Fallen Ketches are shown in-atmosphere frequently. In fact... you never actually see them in space.

Yup. I mean... I haven't seen a Dreg around these parts in a while... but I doubt they've evolved much since then.

Haha I did notice that about the guns before but I figured with everything else in the game just overlook it