Beating stringed instruments with sticks is done in several regions of Europe. The tambourin de Bearn (from the Basque Country) is a sort of minimal dulcimer used to beat out a single chord. The gardon (from Transylvania) is a kind of agricultural cello tuned in unison - three of the strings are hit with a heavy stick, the fourth is lighter and plucked. These both play lower than a violin, though.

I've never heard the erhu called a violin. It's generically known as a "spike fiddle", and it's useful to keep the terms separate since it is sometimes used along with the Western violin, both in China and in the Middle East (which adopted both instruments).

Turkish music has a particular problem keeping fiddle/violin terms straight since there are no less than four different kinds of them in common use.