Hello Maddy737
The distribution of traffic would be regulated by the Load Balancer sitting infront of these AEM instances. Once the request comes through to an AEM instance, it would respond back (granted the resource has anonymous access). The only restriction from a Product perspective can be at the dispatcher level, but I am assuming that when you mention traffic to AEM instances, you're including dispatcher to be a part of it.
Best Regards,
Aneet Arora