So I've been reading Aztlan lately and boy oh boy do I have questions for y'all. I don't know if any of the information contained therein is cross-referenced anywhere else, so maybe this is a dead-end, but:

Who or what are the guerreros? I mean, I realize that they're warrior orders whose memberships transcend platoon or battalion lines and that they're afforded special status within the Aztlaner military. It's also possible that they're all Awakened and they may or may not all be direct employees of Aztechnology.

Any idea as to the truth?

They're mainly large initiate groups for Awakened members of the military (which is a division of Aztechnology Corporate Security, mainly), divided and patterned on ancient Aztec warrior societies.