Hi @anabananei ,
What is currently achievable is to randomly extract five users, but there is no guarantee that these five people will not be duplicated, because Rand() function may get the same result in a small range.
What's hard to achieve is that the second time the user to be sent, the previous user needs to be excluded.
Because it is necessary to record the previous personnel, how to obtain it when the next execution of Flow is a difficult point.
Anyway, I created a flow that randomly selects five users, you could use it as a reference.
Create a list to record the user information, create a new Person type column to select user, and give each user a number, you could consider directly using ID as a number.

Flow configuration:


Please take a try.
Best Regards,