You could argue with match up advantages on certain fights and stuff like that, but the bold part..?
WhosWho probably has the same fighting style as Brook, namely swordsmanship, while in base he's probably already stronger and now he even got a sabertooth fruit, which is probably the strongest out of all mammal Zoan fruits.
Reaaaally difficult to see that happen tbh.
If anything, everything you just said would seem to point to it actually happening. If we can logically comprehend Franky vs. Sasaki or Robin vs Black Maria, we shouldn't make excuses that it can't happen with Brook.
Dont get me wrong, these should be insanely high difficulty fights for literally every Strawhat. They should all be violent as fuck and should push everyone to their haki and new power limits.
I say it like this, if we can comprehend Luffy beating Kaido/Big Mom this arc (with or without help), we can comprehend his commanders to fight Kaido/Big Mom's commanders, just as we can comprehend his 6 "weaker" strawhats to fight the weaker but notable Beast or Big Mom pirates.
There shouldn't be exclusions. This is the arc where the main characters should fundamentally grow into a monster of a crew to the endgame. Even if there are a few more arcs left after this.