Let's start posting some data about Alluvion Skirmish and augmentation results.
There are 8 types of Stones, they are divided in 2 groups: Snow and Leaf
There are also 4 categories: Slit, Tip, Dim, Orb
Each stone also comes in 3 different quality levels: NQ, +1 and +2
To enter Skirmish we have 5 different items that can be obtained from global treasure pool or personal chest in Ra'La and Cirdas Skimishes: Eudaemon Blade (T1), Cape (T2), Ring (T3), Sash (T4), Shield (T5)
Basically you just take a Simulacrum KI for Cirdas and Rala in any of the combinations they come with and "empower" them with one of the Eudaemon items, and that's it, you get an Alluvion Skirmish entry KI.
Edit:
The one about tiers for the Eudaemon pieces is just speculation atm. SE presented the pieces to us in that order (which happens to be alphabetical order), and Oswold requires more gil according to that order, which leads to believe there's a "tier list" between those pieces.
Drop rates so far instead (judging at the numbers sold on AH) seem to conflict with this tier list, or if there is a drop rate difference it's nowhere near as noticeable as the one between old parts T1 and T5.
Results:
Keuranos:
Macc+15, Mab+15 (not bad at all )