"When it became a ballroom dance was in the clubs in the Argentine where again it had the circular motion and much tighter groups because of the space problems."

That's a perfect example. Ballroom tango people consider the curved nature of the walks sacred... argentine tango dancers are like "what?? I guess if you want to, but it's no requirement".

Or the foot to foot action - argentine tango dancers will drag their feet if they feel like it and move in all sorts of ways that would not fit the ballroom idea of tango's history.

So some selective memory is going on. Ballroom seems to have enshrined some dance characteritics. Wheras argentine tango seems to have enshired the interpersonal philosophy, leaving the technique free for reinvention.