This is very annoying because in battle archers became soldiers, and civilians drop their tools for a useless sword and stop working. It is advisable to delete this functionality and let the NPCs be equipped only trough the UI.

Why are your civilians involved in a battle ?
Also, the item catch is protected by game rule "mobGriefing", if you want to disable it.

Sorry I used wrong words, my civillians are not involved in battle but if I drop a sword near them they will catch it and stop their work. In addition you can't say to disable that game rule, that will prevents all mob from griefing including creepers and this would be a game limitation. This bug occurs only when the NPCs pass over swords and for nothing else.

Alright, i'll disable that for civilians and archers.