Can we configure multiple weblogic admin servers with one EBS 12.2 application instance?

We are under the process of upgrading our EBS to 12.2.9 , in our current EBS 12.1.3 instance we have 5 EBS internal instances and 10 EBS external DMZ instances , which are managed by F5 load balancer to achieve high availability. We upgraded our test server with 2 node application using shared appl top, the EBS 12.2 upgraded instances is considering node 1 as primary and the 2nd application node as slave...primary is only having the admin server...the second node is just having the additional managed servers and the node manager only......we know that this is the default configuration