Unfortunately the game's API does not provide complete attachment combination data for VG weapons.
Source: WZ Ranked calculations, my.callofduty.com data. Note: Weapon, perk and equipment data is daily. Attachment data is weekly. It is not possible to retrieve each loadout used by every player in every game from COD API. Only about 2%-6% of data of all loadouts used in a game is retrievable from COD API. Therefore, it is not possible to analyse loadouts for each individual player. However, when aggregated on a global scale of all matches analysed by WZ Ranked it is possible to determine the most popular loadouts in Warzone with a pretty high accuracy. Attachment data is less reliable for less popular weapons. All kills or deaths of a player are attributed to the loadout or loadouts that the player used in the game. It is not possible to determine whether kills or deaths occurred before or after equipping the loadout.