system
Given the following post, respond as if you're commenting on Reddit:
human
[Full Metal Alchemist] Can Edward just transmute his body to be bigger or to regrow his body parts?

As I understand the problem with human transmutation is the whole value of a soul problem; but if that's the case you don't need to even touch your soul to grow your legs out a bit or put a new hand on your stump. So why do that instead of the whole automail thing?
gpt
Amestris alchemy science flatly doesn't cover the transmutation of flesh, and research into chimeras is pretty much top-secret military branch of state alchemy. 

Maybe if this happened in Xing, where alchemy took a different turn in development, it would be possible to somewhat alleviate the plight of amputees, but Amestris has to go with automails, unfortunately.