I recently received the following Idoneth Deepkin stuff in a trade:
-50 Namarti Thralls
-10 Namarti Reavers
I have a lot of conversion experience and didn't see myself needing all those thralls, so I was planning on converting one box to get a Soulrender, Soulscryer, and second Tidecaster, then converting the rest of the box into Drukhari models for 40k. My thoughts on a list was:
Tidecaster as General for reversed Tides
4x10 Namarti Thralls
1x10 Namarti Reavers
2x6 Ithlaen Guard
Akhelian Cohort Battalion
Dhom-Hain Enclave, since I won't be playing for much of a turn 1 charge I don't think I need Fuethan. My army list just isn't able to take the traditional "Eels up inside ya, finding an exit where they can" style Idoneth list that it seems is fairly common in competitive events.
Battleplan would be to run the Akhelian Guard to the front, hopefully soaking as much upfront enemy firepower as possible on their 3+ unrendable saves, and aim to have as much of the army in combat turn 2 as possible.
That's what I've got so far! I'm very new to AoS so everything I've done so far is pretty theoretical. If anyone has found amazing tricks you can pull with a double turtle setup I'm all ears, but they really do seem like they're mostly made to be support centerpiece style units.