What is the strongest fictional army Dothraki can beat

[Aldarion]

So Dothraki are incompetent. Really, really incompetent.

So with that in mind, what is the strongest fictional army that a Dothraki khalasar (so 40 000 screamers) can beat?

 

[ATP]

So Dothraki are incompetent. Really, really incompetent.

So with that in mind, what is the strongest fictional army that a Dothraki khalasar (so 40 000 screamers) can beat?

goblin army from Hobbit/book,not movie/
They were not stong,only had numbers.