Disappointed in one Endwalker Aspect [SPOILERS]

[Lauront]

The elements have intrinsic astral or umbral propensities, but any of them can be rendered astral or umbral, as BLM will attest to. The Source having things backwards on it does not change that and was not implied to do so to my recollection. So the presence of all six elements does not imply a mix of astral and umbral in and of itself. The EE goes into this as well, on how whether an element is in an astral or umbral state in the world can affect how it manifests, e.g. umbral fire being a dry heat.