Comment on "On selecting a low-order model using the dominant mode concept"

In the above-mentioned paper [1], the authors presented a criterion for selecting the order of a low-order system to approximate a high-order model. Their criterion is very similar to what has been presented before in [2] and [3]. The authors claimed that the extension to handle systems with complex eigenvalues [3] is incorrect. Also, they used examples to show the superiority of their criterion. In this comment, it will be demonstrated that their claims are not absolutely correct.