I have for example 5 webRTC peers connected to each other through COTURN server (turnServer1). All of them are behind symmetric NAT which means that they cannot establish connection without TURN server. All these peers are sending MediaStreams with audio and video to each other which makes TURN server to run out of its bandwidth and I cannot add another peers to this media conversation. Right now network has this structire:

and if this network is going to have 10 peers where each peer uses approx. 100kB/s of bandwidth than TURN server requires 1010100kB/s=10000kb/s and if there are going to be 100 peers than this number will be raised to 1000000Kb/s. So I am interesting is there a way to transform such webRTC peer to peer network into something like this:

With such network architecture TURN server bandwidth burden can be decreased almost twice. Is it possible at all and if it is that how this can be implemented?
Any help appriciated!
In general you do not need to do anything special if you have two peers on different TURN servers (like peer 3 and peer 10 in the second example) since TURN presents itself as plain UDP to the other side and turnServer1 is not even aware that it is talking to turnServer2 rather than a peer directly.
For such an architecture you might want to consider a SFU (selective forwarding unit) instead of a p2p/full mesh with TURN servers.