I said it's a variation of track 18. You know, a remix? They changed it a bit to fit their needs?

There's only two tracks on the 3 OSTs that has the "soya soya" vocals as you call it, and that's "Strong And Strike" from OST 1 and "Hokage" from OST 3.

You won't be finding that exact bit of BGM on any of the current soundtracks and likely not on any future ones either.