Intuitively, it would make sense if combat were the #1 driver of fame. I'd suggest you keep all current bonuses, and add: +1 fame for each +1 CP; bonus for MVP; bonus for PVP victory.
Most people's fame would roughly double, but those who play a mostly economic game would benefit less, while those who fight all day, every day, would benefit more (making up for not having a life).
FYI, I'm in the roughly-double group. This isn't about self-aggrandizement.