That's right. Levi Morrison and I created a second Slurm fairshare algorithm, Fair Tree. Our first algorithm, LEVEL_BASED, was accepted into Slurm and became available in 14.11.0pre3 about one month ago. Fair Tree was accepted into Slurm in time for 14.11 and replaced LEVEL_BASED.
When given the same inputs, both algorithms produce effectively equivalent outputs. The objective of both algorithms is the same: If accounts A and B are siblings and A has a higher fairshare factor than B, all children of A will have higher fairshare factors than all children of B.
So why bother writing a new algorithm three months after the first one if the first algorithm successfully solved the same problems?