I think you are mixing Roger with Luffy...
Oda clearly called Luffy representative of Fame because only Luffy, Nami and Zoro were present when he said the triggers gathered.
The was nobody else there except for those 3.
And he subtly has hinted at who those same triggers are among Cross Guild.
Luffy is obviously Fame, there is no character in the show who will be even close to as Famous as Luffy.
Others will beat him in both Power and Wealth.
If Usopp is Fame, he will lose in Fame to Luffy so it ends up that Usopp is not Fame after all.
Representatives of Fame, Wealth and Power cannot be beaten in those by others.
If Luffy is more famous than Usopp, Usopp isnt Fame.
If Luffy is wealthier than Nami, Nami isnt Wealth.
If Luffy is stronger than Zoro, Zoro isnt Power.
That's because you interpret those Three Words this way, the Manga never said this directly
Three Early Arcs i mentioned were created to answer this question
What does Power mean? Morgan & Zoro had different Answers
What does Wealth mean? Buggy & Nami had different Answers
What does Fame mean? Kuro & Usopp had different Answers
Zoro was Introduced as Captured & Weaponless, He is Power-Obsessed who Abandoned his Power
Nami was Introduced saying that She gonna give her Treasure to buy a Village, She is Wealth-Obsessed who is Abandoning her Wealth
Usopp was Introduced as Village Annoying Liar, He is Fame-Obsessed who Abandoned his Fame/Reputation
While Morgan, Buggy & Kuro were complete Opposites
They wanted Power, Wealth & Fame (Good Reputation) at all Costs
Kaidou, Blackbeard & Final Villain are gonna be the same
Kaidou wanna "Conquer" The World
Blackbeard wanna "Buy" The World
Final Villain wanna "Inherit" The World
We know that Zoro wanna keep getting Stronger
We know that Nami wanna keep getting Richer
We know that Usopp wanna keep having more & more Stories/Adventures to tell
But that's not what the Story is about
In each of those Three Arcs, Oda created Koby, Chouchou & Kaya who would learn True Value of Power, Wealth & Fame
Zoro's Arc taught Koby that "Your Will" is True Power
Nami's Arc taught Chouchou that "Things Your Protect" are your True Wealth
Usopp's Arc taught Kaya that "Dreams" are your True Fame
And as Story Progressed, what did We learn?
Luffy have "Will of D." same as Roger
Luffy's Treasure is "Straw Hat" that Originally belonged to Roger
Luffy's Dream is only shared by Roger
This is why Only Luffy can Surpass Roger, cuz He Inherited his Will, Hat & Dream (Power, Wealth & Fame)
So when Usopp is presented as Luffy's Equivalent of Fame, it doesn't mean He will become Equally Famous or Equally Influential
Zoro, Nami & Usopp are Re-Creation of how Will of D, Straw Hat & Joy Boy's Dream Originated
But instead of Past Events only leading to Luffy Inheriting these Three Things
This time, the Whole World gonna be included
Luffy + Zoro gonna Inspire The World just like They inspired Koby (You can achieve anything through Cheer Willpower)
Luffy + Nami gonna Inspire The World just like They inspired Chouchou (Anything can be a Treasure)
Luffy + Usopp gonna Inspire The World just like They inspired Kaya (Don't ever Stop Dreaming)
Only through this Three Achievements, can the World be Villain-Free
Which is what Luffy is gonna achieve at the End
Just like Chopper's Dream is to End Sickness, Sanji's Dream will End Hunger, Jinbe's Dream will End Racism ... etc
Luffy's Dream gonna End Villainy (But He needs Zoro, Nami & Usopp to do so)
So Overall, you're comparing them to Luffy using how Villains Define those Three Things
Not how Luffy/Roger Define them