The original 1815 PLM Tourbillon seems to be the collector piece at the high end, so clearly people believe it to be important. Perhaps it can never be as significant as the Dato and Lange 1 are it's impact on Lange itself or the broader watch world was (is) relatively limited. The Lange 1 was bold in design and is unquestionably THE identifiable Lange. The Dato spurred others in action and again carries a "signature" design element in the big date. And following this same thought process this is argument one could have for the ZW too maybe.
Re the drift off topic, it is relevant. Is there a chance that ALS fades to mass market oblivion in another 20 years? That would surely impact the historical view in some way.