Casse Druids and reforms

[burn_again]

Well, just open the recruitment viewer, select Casse, click on a province and then View--> Province details. Check "Detailed info". Every unit in Complex 4 is recruitable with the first reform. The units in Complex 4, Level 13 are the new ones in the Time of Bondsmen. Every unit in Complex 5 is available in the Time of Soldiers. The units in Complex 21 are available through your regional barracks.
Just give the recruitment viewer a try, its a bit much to list every single unit here.
Druids are available in the highest level factional barracks. You won't need any shrines or something, there are just factional and regional barracks.