Small improvements....

I wrote:
Set xRng = Range("X2") '***new***

Change to

Set xRng = Range("X2:X112")

Or more generally, after determining nRows:

Set xRng = Range("X2").resize(nRows)

I wrote:
xRng.Offset(0, i - 1).Resize(nRows, 1) = _
Range(rngs(idx(i)))

With the change above:

xRng.Offset(0, i - 1) = Range(rngs(idx(i)))