good idea: marry a blacksmith so you can get free swords whenever 

Better idea; become a miner and then marry a blacksmith so he can have the required materials for you to get free swords whenever. 

Make a harem and marry a full production chain

Monopolygamy.

I mean, if your harem is full of blacksmiths would that make it a polyhammerous relationship?

You could make a whole polyarmory