If anyone thinks Fujitora being damaged by Karasu is damaging Fuji's portrayal, I'm sorry but please quit powerscaling and never touch One Piece again since this is just an insane lack of reading comprehension.
Your headcanon of how strong Karasu is =/= reality of Karasu being above your "Yonko commander level" assumptions.
Honestly depends how it's done. It should came as no surprise if given a free hit Fuji is susceptible to damage. He isn't a logia nor a natural durability freak.
The reason this sounds worse than we thought is cause it wasn't even Sabo who gave him the injuries.
If these spoilers are true, I'm gonna give Fuji the benefit of the doubt and say it's the combination of Fuji not focusing on Karasu and also being unable to use his df to flex his AOE. I'm sure the chapter ends with Fuji retaliating and making the commanders shit their pants.
In neutral ground Fuji would probably flatten multiple rev commanders. But under these conditions Fuji is the most exposed. Greenbull honestly should fare better in theory.