Re: STs and Hemo. Spawning question
Oh no, I'm not aruging that Yamataians 'could possibly' make organic machines to do this - they could very well be able to do that - it's just most of the literature on neko both OOC and ICly has favoured a far more mechanical explanation.
The nanomachines for instance which, if they are capable of making organics to replicate everything, would almost certainly be organic themselves - and they've never been described as anything but "mechanical" and "built". So, if one of the most prevalent compounds in the body is mechanical (blood) then there are almost certainly other mechanical, non-organic, aspects as well (I believe there are references to neko brains being built tech similar to PANTHEON - which, unlike Elysian computers, isn't organic to my knowledge). Regardlessly, incase of neko (and possibly yamataians) the distinction between an organic and mechanical component is probably impossible to make without a laboratory analysis.
Also, you're looking at the analogy the wrong way. Remember we're not talking about humans here. If someone stabbed a neko through the heart, it wouldn't kill them. In fact, it'd probably just piss them off (because they don't need a heart to function). In fact, the only way to kill a neko easily is to blow its head off - the equivalent of totalling the engine. Actually, it's exaclty the same because, yes, Yamataian scientists really could just replace the brain and the body would start to work again (if the few threads dealing with medical technology are any indication anyway).
That said, I think we need a new word here that describes a semi-organic sort-of-not-mechanical entity. Regardless, the current term used to describe an organism that has biological and mechanical components integrated into it (on any scale) is 'cyborg' so that's the best word to describe them atm.
Also, much <3 to discussions like this. Helps to flesh stuff out =p