Doing the same rank-based comparison for the CMs this time, we observe that the syllable and morph-based models have the same average rank of 1.5, whereas the word-based model has 2.8.
a closer look reveals that the syllable-based CM paired with NO-LM is an outlier because NO-LM approach allows variety at the output but when the unit of the confusion model is as small as syllables, it produces too much variety that deterio-rates the discriminative model.