Heman was blessed with a large family, and the extensive record of his sons reflects this rich lineage. When reading through the long catalog of his children, a natural question arises about how to properly divide and count their names. Specifically, one might assume that Romamti Ezer refers to two distinct people because it is formed from two separate words.
However, the accepted approach is that this actually represents a single name belonging to one individual. This conclusion is clearly supported later in the same historical account, where this son is listed again and unmistakably identified as one person [מלבי״ם].