Correct, but that doesn’t mean the IB set is the “best.”
There are three potential weapon setups to use, and each has advantages and disadvantages. Many folks use the IB setup, but fail to consider that using the BK swords allows you to keep Bloodfunnel and Into the Fray, the latter of which can be a huge DPS boost in density.
For more information, consult the complete guide: [Guide] Zodiac Rend (Season 20)