I guess the question is...just because they have the same names, are they really the same forms?
I've always heard Yangjia qiang and Liuhe qiang are interchangable terms, but when you look at huge assortment of forms with those names it seems not to be true. On the other hand, filter out some of the flashy opera moves and they boil down to the same handful of techniques and strategies.
More importantly...how were these arts trained back then? I've seen staff training in China that involves paired training that more closely resembles Japanese formal paired kata, but teachers in China seem much more content with teaching solo taolu.