system
Given the following post, respond as if you're commenting on Reddit:
human
[A Song of Ice and Fire] How do the faceless men assign and manage tasks since everyone is No One?

It would suck to be a manager at the house of Black and White. Imagine a schedule of chores on the wall, and every single box is "No One".

"Who is assigned to the assassination today?"

-"No One is tasked with the assassination."

"Who's cleaning the fountain? Someone pissed in it."

-"No One is cleaning the fountain."

...

"Sir, no one has cleaned the toilets for the past four months."

-"Good."
gpt
We know there is an unspoken hierarchy. Arya is "trained in" by and takes her first assignment from a specific No One. It's possible that this single one is in charge of all the Faceless Men. Maybe an assignment comes in, and this single Faceless Man assigns it out. 

Alternatively, maybe there isn't a true hierarchy or command structure after you are fully trained in. Maybe the assignments come in, are discussed, and somebody just chooses to take each job. In this scenario the faceless men are all equals and pool resources.