Hydrologic sorting is both a very logical explanation and a provable one. The creation of fossils requires a specific set of conditions. Both of the above statements, after study,will give pause for thought concerning the flood.
P.S.- Your tagline...no worries. There have been too many proofs.
Maybe a river overflowed and the fish got trapped in a small pool of water and died, right after it froze. The next spring sedime t was washed over the school pool of fish.