All those compact heavily toothed green to blue plants are hybrids of Agave oteroi with a combo of Agave kerchovei and/or titanota. I can see slight hints of a midstripe, which is something that Agave titanota does not have, while oteroi does.
True Agave titanota is extremely light grey (almost white in high light exposure settings) plants are generally not as compact with longer leaves that have less teeth, but corneous margins that can start out anywhere from black, brown, to yellow. So Steve's plant probably has some titanota genes in it, but is not pure titanota.
There are large areas near the type locality of Agave titanota - which is extremely difficult to reach - where oteroi and kerchovei grow together and clearly freely hybridize, but among plants grown from seeds from that area you find specimens that have a lot of titanota characteristics. A lot of the plants you find in the trade now that should be named Agave oteroi or oteroi hybrid were brought to market before Agave oteroi was officially described, so before they would stick the name titanota on it, but that was incorrect.
