Please correct me if I'm wrong (as I'm not a specialist in this topic) but as I understand this typical dual driver has one output bore. Thus, how can you say that you have 2ways in dual driver which have one bore?
If the dual driver had two output bores then yes you cold put two, separate crossover point on each part of the dual driver and have 2way system.
But a 3-Way crossover universal only has one bore that leads to your ears. A dual driver has a output 'slit' for each driver, but only one bore for the two 'slits'. Technically you can break the parallel connection between the dual drivers, but how good it sounds after you crossover it like that I really don't know. Also is there even enough space in your shell to fit a 7-way electronic crossover in after stuffing 8 drivers?