This is a bit late but if you're still having issues, did you remember to assign them properly? They need to be assigned to beds, patrol points, training locations, etc.

Hey there. I did all the things. I think I may have had too many thralls or they maybe didn't like where they were walking. I ended up not being able to do much except with just a couple of thralls.

I have a base with around 30 thralls myself and mostly everyone is doing what they should without issue but sometimes a few can end up standing around not doing anything due to pathfinding or whatever. Can't think of any reason why it wouldn't work if it's set up properly but so far I've only have them set up for training and nothing more complex like patrolling or logistics.
Just out of curiosity, how do you have them set up?