I used to use Whirlfloc in every batch and then used Gelatin in the keg. Then one day I forgot to add the whirlfloc. I fretted, but, I figured the Gelatin alone would have to be enough.
Low and behold, Gelatin alone cleared that beer as good or better as any batch I had brewed before.
The next four batches I skipped the whirlfloc and just used Gelatin in the keg. Every time the beer was crystal clear.
I am not saying this is a good practice. "The Beerery" says Gelatin oxidizes beer. I can't taste that, but, I won't say he is wrong.
I just thought I would report on my results. I surmise that maybe the lack of whirlfloc is leaving more protein for the Gelatin to grab hold of and therefore the Gelatin works betters better in this scenario. But, that is just a guess.