While reading the MoPub best practices https://developers.mopub.com/docs/mediation/waterfall-latency-and-best-practices/ I found this:
Keep items at the same priority: If you set up items at the same priority, then MoPub Marketplace, S2S networks, SDK networks, and direct-sold ads can compete with each other for the maximum CPM. We are obligated to show a network creative anytime we reach out to a network and it successfully returns a creative, so we have to wait until both Marketplace and your network partner have returned a result. Parallelizing requests by having items at the same priority improves your latency and CPMs.
Does it mean that I should keep, for example, 2 different Networks at the same eCPM level? what will happen in this case? both requests will happen at the same time? how MoPub will choose which Ad to show?