The Aasamir are in Monsters of the Multiverse, which is a OneD&D book. The Ardling is doing a different thing, filling a gap for players that WotC feels is PHB worthy.Exactly. My issue with WoTC regarding the Ardlings is that they are IMO overlooking the Aasimar, who have been the Tiefling's counterpart since 2e Planescape. I have heard that 1D&D might keep them along with the Ardlings. But if you wanted a furry planetouched individual, you really don't need to look farther than the Guardinals as their planar ancestor.