From listening to comments and reviews from wildlife photographers who actually use the cameras (not just reviewing them) there doesn't seem to be much of a difference, With Nikon outperforming the others in some circumstances and vice versa.
The reviews are often contradictory. e,g. I’ve seen reviews (more than one) which claim a big plus for the Z9 AF was that unlike their Sony or Canon cameras, the Z9 wasn't fooled by falling snow. A review I read recently said the exact opposite and reported the Z9 being fooled by falling snow was something Canon and Sony didn't suffer from.
It does seem that the Z9 currently needs a bit more thought from the photographer to choose an AF options than others, but that may change with the next firmware update. Which is likely to change more quickly than Sony/Canon offering the two Nikon lenses you mention.
I'm not sure if it was the video that was linked to, or another one from Jan Wegener, but in one of his videos he discusses that after using the Z9 and experienced the Nikon lens range, he is giving serious consideration to switching to a Z8 once it came out (assuming the Z8 is a mini Z9), as he didn't want the weight of the built in battery grip of the Z9.
If you haven't seen this, Steve Perry looks directly at the Sony vs Nikon question here, and this is after a lot of experience using both systems.
View: https://www.youtube.com/watch?v=mxiBKMgxExc
Steve Mattheius is someone else who temporarily switched to a Sony A1 system from Nikon DSLRs, and then after the Z9 came out, and after running both systems for a spell switched back to Nikon.
I'm not trying to argue the nuances of one make being better than another, I'm just not that convinced that Nikon is "that much worse" than the others, and that the best and worst varies with circumstances and the skill of the photographer (firmware updates have helped).