I feel like "chaH" in this sentence is entirely unnecessary since the object "them" is already indicated with the prefix tI-. Is there actually a distinction in meaning whether the pronoun is used or not?
Other than possibly (for instance) when speaking the phrase aloud, one might place emphasis on "chaH" as a specific subgroup of all those present... e.g., chaH tI'IjQo'; maH tI'Ij! (don't listen to THEM; listen to US!)
Just some thoughts I had. Anyone have some insights on this they'd like to share?
You are correct. chaH is entirely unnecessary, but not incorrect. There is not really a distinction, but perhaps a subtle difference. Repeating the object with a pronoun stresses it a little and your example sentence is exactly the kind of situation where one might do it. Except you need to change the imperative prefix for "us": chaH tI'IjQo'; maH gho'Ij!