HOW EXCHANGE CERTIFICATE CAN SAVE YOU TIME, STRESS, AND MONEY.

I have a DAG ecosystem with 6 servers(2Mailbox+2CAS+2EDGE,Exchange2013 CU21), on that situation, I just do the procedure in any one mailbox server (one example is MX1SVR) after which wait around the new certificate to replicated to one other five servers through some hours ? OR i ought to run a similar system on a single CAS server and a single EDG