  Half-Heusler phases are among the most extensively studied thermoelectic
materials. Bipolar thermal conductivity analysis performed for their sub-group
based on rare-earth (R) metals, RNiSb, indicated on high mobility ratio in
favor of electrons. The suggestion found its experimental verification and led
to significant improvement of thermoelectric properties in $n$-type doped
series ScNiSb$_{1-x}$Te$_x$. Recently, an alternative interpretation of
transport properties in ScNiSb was proposed, where multi-parameter fit lead to
mobility ratio in favor of holes. In this work we discuss the details of
electrical properties and thermoelectric performance of ScNiSb in context of
structural disorder. The article considers also relevant assumptions regarding
band degeneracy and scattering mechanisms for effective mass modeling in
ScNiSb. Lastly, technical difficulties of the model proposed by the others are
addressed. We believe, that the provided insight will be useful for
understating electrical transport in half-Heusler compounds, which can
contribute to further improvement of their thermoelectric performance.
