Maybe another way to handle that is to simply take the System out of it. As GM, I can assign different rewards to every fight. I could reward tougher fights with powers, and easier fights with Favor or Gold. Favor could be used to gain story benefits, such as gaining allies for a battle, earning conquered territory, or even getting a moment alone with Her Majesty. Gold, on the other hand, would be used for more tangible yet transient benefits. You could buy body armor that raises Defense but breaks when you take a wound, an ultra-powerful weapon that's permanently lost when disarmed, and stuff like that.

P.S. If you're not keen on the story details, I have a few other variants in mind.