SMG's such as the M11 or HFC 77 would be classified as pistols if used in semi-auto mode. These could be used by either the Civilian Survivors or PMC. In full auto, these could be used by US Military Specila Operations.
Our goal for the game is to provide different adventure experiences based upon 1) the skill level of the player 2)the types of weapons and gear needed.
The Civilian Survivors will have the easiest types of zombies to fight against and less complicated mission objectives (stay alive, finda ammo, move to a secure location, etc.)
Private Military Contractors will have more complicated missions with less restrictions on their actions (Find and secure a rogue scientist, recover a sample of the virus and vaccine from a research facility, etc.)
US Special Operations Personnel will have extremely difficult missions with very specific objectives that will require team work, communication, and specialized weapons. (Gain entry through tunnels, use a robot to locate a nuke, recover specific items from xxx).
While weapons and gear will be important to each role, players should select the unit they wish to be a part of based upon their skill level and not just their gear.
Thanks again for the questions.