Other plugins that allow you to call a wide range of networks through PMK actions can be used to create home made mediation suites.
Combined with web/https actions, you could host a txt or xml list on your own website which could be accessed and downloaded by any copy of your game at any time, using this short list to define the percentage of use of this or that network, it's quick to do in a FSM since you can send randomly events for example according to weights (your percentage divided by 100 so it goes from 0 to 1). Then all you have to do is open your respective networks' dashboards and compare their, say, eCPM rates.