Chicken Littles FC No, wait, that's the name of the team for the BigSoccer posters posting about Atlanta...
Atlanta Locos ticks off a lot of boxes. Plays off the early Terminus name where the city originated at mile zero of the rail line to the midwest. Can easily then incorporate the train engine theme. Also would play to the Hispanic population because of the double meaning of the word.
That would be either a great unofficial nickname or a great name for the supporters' section. Alas, The Don & Co. would never sanction it, official-like.