Blacksmiths could detect how many iron golems are within a certain range, and if not detected spawn a new iron golem. This will ensure that if a player is not actively protecting a village, it will end up regaining protection passively.

This means the village will passively have a set amount of golems at all times (could limit to three), because at the moment villagers are purely reactive, and this makes them more vulnerable

Just had an even better idea, make it so it's a ratio to villagers so it scales with size of village.

Also a config to choose what level a blacksmith would be, on hard difficulty my modded setup has lots of villager massacres :(

Hopefully this is an easy one?