The techniques are not identical. The use of the bow, and the types and use of ornamentation are not the same.

That's not technique.

Technique covers being able to pitch notes accurately with your left hand, to bow cleanly with your right hand with a maximum of efficiency, to choose bow position on the strings for various tones, and to coordinate the movement of both hands accurately. That's all. (OK, vibrato as well, but that's rarely an issue for folk.) And that's what classical teachers know best how to teach, because that's all they do for the first 2-3 grades.

Everything else after that is style. And that's where you get folk-specific - see earlier posts.

Graham.