I would probably go further, and say that it should not encompass more than one step - again, this requires a lot of deconstruction of ones own dance.
And I do not decompose and try all possible variants - I have some kind of a Tango5 project:
I try to memorize not more than 5 moves, attaching them to the fingers of my left hand. At a milonga situtation maybe I'll remember at least one or two. After trying them some times - successful or not - do I delete them to get place for new ideas.