Sarmatian origins of the spatha?

[Dan D'Silva]

Well, i believe that as shape and dimension of blade, Naue II can be considered the ancestor or grandmother of most of following long right swords.

I'm not entirely sure what you mean. If you're suggesting that contact with cultures on the border using the Naue II influenced the Celts and Sarmatians to make larger swords out of their daggers, that would be an interesting hypothesis, especially if you could establish that the Naue II abutted the development of these swords in place and time. Not knowing of such evidence myself, I'd attribute wanting a longer sword to simple utility in horseback fighting.