The dev don't choose the Ads. They put a SDK from an external adpartner (UnityAds, TapJoy, IronSource, whatever) and then the ad network display the stuff.
The dev don't even know what will or what was displayed in their game.
Raid Shadow Legends pays a lot to saturate the market, so the adnetworks show them a lot.
I checked and the ad I received are from IronSource. It is an Israeli unicorn worth more than 1 billion USD. If you want to go talk to them directly good luck finding the correct person .