Fuji already actively worked against the WG multiple times, and verbally voiced his disdain for its actions. I posted some, but there are plenty.
Fuji let the revs go two times, Sabo even said he would be in trouble if they found out back in DR.
Letting aside the meaning of all this, all this construction wouldn't have any sense if it was just to let Fuji do what a character without any of this would have done. Koby is the same: do you think he'll fight for the WG when the times come? And Smoker?
As for the Yc1/Yc2 it is in the manga. RHM/YC1 had always a special portrayal, some more and some less, but all had. Katakuri had in WC, Benn had since forever, Ray had it too, but the same could be said for King and even Marco.
Yc1 and 2 are comparable, but between Katakuri and Smoothie or between Ray and Scopper there has always been a wide chasm of portrayal (and often a hierarchical difference too).