Greg responds...

There have only been two models of Steel Clan Robot.

The original model, commissioned by Xanatos, seen in "Awakening, Part V" and "The Edge" and "Double Jeopardy" and "The Price", etc.

And the Iron Clan Robot model, commissioned by Owen Burnett, specifically to battle Oberon and/or Titania, as seen in "The Gathering, Part II". These are larger, and their chassis are made from iron as opposed to steal, but most of the other tech specs are the same.

The so-called "Advanced AI" model that I assume you're referring to from "The Edge" was not a robot at all. But a suit of armor (red in color) that Xanatos wore. Though from the outside it looked like a red version of the robots, it in fact was obviously constructed very differently. I'm not saying they didn't use any of the robot tech on the suit, since they obviously did, but it also required a separate develpoment phase.