When you click on the loot chest to see what the bounty rewards are, the game tells you “earn some coins for the mercenaries in your party plus a random one of the following”, displaying three mercs.
In fact completing the bounty awards work the opposite way of what it says. You get coins for all three of the mercs displayed in the bounty, plus a random one from your party.
You need to either fix it so it works the way you say it does, or update the text to match the game.