Thats interesting, but I don't think the social dynamics of such a game would work. The situation is unstable, where either the builders can't keep up and quickly lose their factory (and probably quit) or the PvPers get surpressed and/or just ignore the factory.

This is kinda what happened in modded PvP Minecraft servers.

But there are already some team based "production line PvP" games like Mindustry and Foxhole.