and circle-dancing is slavic, greeks & byzantines adopted it after the slavic migrations.
So when exactly do you claim slavs came in contact and influenced the ancient greeks and ancient peoples form of dance?
Dancing in a circle is an ancient tradition common to many cultures for marking special occasions, strengthening community and encouraging togetherness. The circle is probably the oldest known dance formation. It is found even today in the community dances of many cultures, including Greek (Greek dances surviving from ancient Greece (chorea)), African, Eastern European, Israeli (see Jewish dance and Israeli folk dancing), Serbian, Irish Celtic, Breton, Catalan (sardana), South American and North American Indian. It is also used, in its more meditative form, in worship within various religious traditions, including, for example, the Church of England and other Anglican Churches and the Islamic Haḍra dances.