- Vickers K is not fired on the move by any infantry units which normally fire their LMGs on the move.
- Bren gun is only fired on the move by Commandos and Airlanding Officer. Any other infantry units which normally fire their LMGs on the move - they do not.
In Vickers K case, when the weapon is picked up it always adds the same slot item, regardless of any unit types a given squad may have. This might be intentional behaviour, similar to how Panzerschreck doesn't have any "elite" variants. Still, it is a strange exception for Vickers K among all the other LMGs.
In Bren gun case, there are 3 different slot items a squad may receive when picking it up:
- commando_bren_light_machine_gun_mp: exclusive to Commandos and Airlanding Officer, it can be fired on the move and has very high accuracy to reflect the "Heavy Weapon Experts" perk.
- sapper_bren_light_machine_gun_mp: theoretically exclusive to Royal Engineers, it has roughly 90% accuracy of the Commando variant at all ranges, but cannot be fired on the move. Bonus "feature" - Soviet Combat Engineers and USF Assault Engineers also receive this variant, because they all share the "engineer" unit type.
- tommy_bren_light_machine_gun_mp: what everyone else gets. Roughly 60% accuracy of the Commando variant at long and mid range, about 76% at short range, cannot be fired on the move.
Simply put, whenever a fire-on-the-move infantry squad (Paratroopers, Rangers, Obersoldaten, Airborne Guards) picks up a Bren or Vickers K, they perform exactly the same with it as any other squad - bar the commando and engineer units above - and can't fire them on the move.
I'm not saying that those fire-on-the-move squads should use the same Bren variant as the Commandos (again, it's extra strong to reflect "Heavy Weapon Experts"), but them not being able to fire those guns on the move seems like unintended behaviour.
Proposed fix: create separate weapon profiles and slot items for Vickers K and Bren that can fire on the move. Add a requirement action to the on_pickup_actions that grants the fire-on-the-move variant if "lmg_user_fires_on_the_move" unit type is present in squad's loadout. In Bren case, also add a requirement that the commando unit type is not present, so Commandos and Airlanding Officer receive their proper powered-up version of Bren. I can provide the working xml changes if needed.