I can't quite follow all that, but it sounds like you want to use an intermediary server to discover the source UDP ports for Clients A and B so that A and B can simultaneously send UDP datagrams at each-other, thereby opening NAT rules and (eventually) allowing the traffic through.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.