I have read on session affinity for ingress and istio, which is based on envoy

I understand session affinity can make the same header go to the same pod. but say a single header is doing a large amount of requests and a single pod cannot handle it, is it possible to have multiple pods/or a service affiliate with this header and load balance the requests.

Is there any way to have session affinity on a group of pods, doesn't have to be ingress or istio