Pokemon black duotype run

For those who dont know what a duotype run is the main rules are,

• You declare two types at start of the run.
• Each pokemon on your team should have atleast one of their types match one of the declared types.
• The run officially starts when you can catch your first pokemon of said type.
• A hm slave can be kept incase it is required.

So I recently did a duotype run of pokemon black. I chose rock and ghost as the types as,

1. They did not have enough mons on there own for monotype runs.
2. They combined have a decent spread of pokemon throughout all the locations in the game.

So I got a choice of 6 out of,

1. Gigalith
2. Crustle
3. @Fossil (archeops/carracosta)
4. Coffagrigus
5. Jellicent
6. Chandelure
7. Golurk

I am at gym 7, so the run is not over as of now. My team right now is Coffagrigus, Gigalith, Crustle, Archen, Litwick, and Jellicent(hm slaved to surf and waterfall | not gonna use it | to be replaced by golurk)

The hardest gym by far was clay. Oh my god that fcker is hard af. I had to teach my Gigalith solar beam and give him miracle seed just to get through.

This run officially added sandile, watchdog and driblur lines to rage-inducing mons.

Sandile and co are ground dark types (aka worst type combo for me) with intimidate(hint : My major source of damage is physical). They learn crunch and ground type trapping moves making them painful to go against.

Watchdog : Ughhhhhhhh. Confuse ray + yawn + Super fang.

Exadrill : Ground steel with stupid damage on ground moves + learns crunch.

So an unexpected strategy that I realized was Coff's mummy + Archeops. As for other strategies,

• will-o-wisp + hex + rocky helm on coff (now replaced by shadow ball)
• Acrobatics + mummy on archeops
• Headbutt/anyrocktypemove + weak armour on boldore (now Sand stream + oneshot with headbutt/rock/bulldoze)
• Expert belt on Crustle
• Litwick is kinda meh right now coz of underlevel

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So what are your thoughts on monotype/duotype runs? Ever done any such run?