I danced recently with a young woman from Buenos Aires who started tango just last summer, and spoke excellent English. An interesting perspective on learning, from someone who came to it recently, but in that dream place where the milongas never cease. Reminded me that someone challenged me a while back to come up with a better format for classes. My only qualification is that I have have survived a wide range of them...
The obvious candidate is traditional: guys learn by dancing with each other. I'm not sure there's any reason why that should be a perfect model for us: social circumstances change. This has been tried in London: I've been to workshops where it was men-only for the first hour, and then the women came in for the second hour. It didn't really feel as if worked that well.
People often complain about 'steps', but we can't avoid them. Even walking involves steps! Tete taught 'steps', so did Ricardo Vidort. It's how they are taught that matters. What happens in most mass classes is that cause and effect get separated. Typically, the male teacher takes the men to learn the men's role, while the female teacher teaches the women their role. In other words, the cause, the lead, is separated from the effect, since the effect is learned separately. This works well in big classes since the results are obvious during the class. Unfortunately, this doesn't translate into good dancing with other partners in milongas. Leaders struggle to repeat choreographies they've learned in classes and fail to take account of other dancers around them.
Of course, tango can be taught in small fragments, steps, which can be strung together in classes, much as they would be strung together in a milonga. But one way of reconnecting cause and effect might be for the teachers, around half way through the class, to say 'Change roles, please!' instead of 'Change partners please!' Five or 10 minutes of aimiable chaos might ensue, but that doesn't necessarily harm a class, and it's just possible that a new mutual understanding of how tango can work might arise. Women are often curious about the lead, without wanting to be leaders, and it's always been said that you dance better if you understand the other half.