Synchronize users hotspot, 2 routerboard CAPs

As the title says, I want to synchronize users hotspot, 2 routerboard CAPs (if they use a user, I want the other is deleted, or if a user increases, the other also automatically created.
This is because they already have a Mikrotik CAPs, and the signal does not reach to the whole atmosphere, the owner bought another, and operates independently. I want to work 2 as if they were one.