I don't think iron golems should spawn in the strongholds, but snow golems in snow biomes might be cool if they're rare.

Iron golems in strongholds should be cracked and mossy and kill peacefull things not mobs

Snow Golems could spawn very rarely in snowy biomes (Tundra, Cold Taiga, Extreme Hills+, etc.), while Iron Golems could spawn very rarely inside strongholds. As with the Iron Golems that spawn in villages, these ones would be neutral, attacking you only if you attack them. This behavior would apply to the naturally spawned Snow Golems as well.

Snow and Iron Golems can spawn naturally.