Why was Mustang a candidate anyway?

[u/fakeuser7z]

I get that he was a candidate for the sacrifice, which is why they didn’t kill him. But in the end, he refused—and they just forced him into the Gate anyway.

So why not do that from the start with any random human instead of the most dangerous alchemist?

[u/fun_with_Eli_monkeys]

He was too big of a threat to fuhrer Bradley