I think that's more security through obscurity rather than difficulty. Once the attacker figures out what the 2 hashing algorithms are, the scenario basically

I think that's more security through obscurity rather than difficulty. Once the attacker figures out what the 2 hashing algorithms are, the scenario basically becomes the same as cracking hashes of 1 algorithm of increased difficulty (through number of passes) So, like the other answer implied, the increased complexity of maintaining 2 algorithms might not be worth the obscurity trade-off in the end. However, I am not a security professional either, so perhaps my opinion is not comprehensive enough.