If TRS events are to be distributed via messaging systems without strict ordering guarantees (eg partitioned Kafka topics), a Resequencer EIP pattern might need to be applied. The pattern requires the message order ids to be sequential in order to unambiguously define whether there are any out-of-order messages still missing from the internal resequencing buffer.
I think a single atomic counter is not too much to ask from the TRS server implementers.
http://www.enterpriseintegrationpatterns.com/patterns/messaging/Resequencer.html