Joseph,
This may come as a shock but Litvish and Chassidish families don’t just have differing customs, their entire upbringing, mindset and outlook is very different from birth. For example, expecting Litvish girls to adapt themselves to Chassidish restrictions makes such matches unlikely to work. Your numerous posts indicate that you have no problem with girls suddenly being told they can no longer drive, earn a college degree or work in a chosen profession. However, they and their parents would take strong exception to such mandates.
Not to say it never happens, just as marriages occur between Ashkenazim and Sefardim as do those between people from very different communities. But as a wholesale solution, it’s as “pants and skirt” as your insistence that everyone ditch dating in favor of be-shows.