Algorithm for getting balances of Yandex API clients?

Question

API

Hello.
There is a managing account, for example, 10 clients. You need to get the current balances of all clients.
As I understand it, this cannot be solved by query \ method alone.
Tell me the sequence of actions in obtaining the desired?
If I understand correctly, then initially you need to collect the logins of all clients using the agencyclients method, which will later be used directly to parse each of them and to specify the Client-Login in the request?