How to add more poses to the weapons?

Someone brought this up long time ago. I’ve already made a suggestion about this to be easily selectable through the Hangar menu but it seems unlikely to happen anytime soon. Is there any way I can do it using the editor? Like, I want Carcano Mod.38 to be held like Carcano M41, not just standing still. I have no intention to change the Hangar background or anything, just soldiers with more variation of poses holding guns.