To be fair I know very little of modern ground warfare, but I'm wondering what troops in PLAGF are being issued the new SMG. Based on the publically available pictures they seem to have a rather substantial amount of them, often showing whole units solely equipped with these SMGs (for example in the pictures above) Are these mainly non-frontline units (for example artillary and tank crew) that just use these as a lightweight self-defense weapon that's more effective than a pistol? Or are frontline infantry units using these parallel to, say, the QBZ-191? If the latter is the case I can't help but wonder what the reasoning behind this is.
From my limited understanding, most SMGs' rather poor armor-piercing capabilities make them rather ineffective in a modern military context, especially when encountering sophisticated body armor tech, so I don't think they serve a major purpose outside of self-defense and maybe infiltration/scouting missions?