I am no expert on Pythium, but it looks good to me.
It wouldn't make any difference to me which Triarius I found in your province, but I believe the set you wanted would be #688 (and then 687 & 686 for Principe & Hastatus).
If it really concerns you, I recommend creating a generic game on a large map with all nations for a given era and set them all to human. Then you can view that nations recruitment. Get the unit info screen and then hit SHIFT+I to view the unit number for the one you want.
I'm not sure if Crystal Matrix works with Theurg Communicants or if you have to actually be using the Slave Matrix as well?
On setting population:
I keep seeing folks setting population to 5000. That is positively fine, but just so you know, you can leave that field blank and Dom3 will assign population values as usual. If you want to have no population at all, then assign '0'.
Overall, it is a very nice contribution and I look forward to taking that fortress from them in my next game.
