Hey, sorry for answering this late.
The Miniion module was the the first one I looked into, when I started developing for Terasology. In Pathfinding module you will even find some classes or methods, that are more or less taken from the Miniions. My biggest problem with this module is, its not very extendable. As an example look into
SimpleMinionAISystem. If you want to add new behaviors, you have to add some lines of code into this class. Also, this class needs to know many other classes/components (just look at the imports). I think, a different approach is to modularize the actual behavior of an entity into much smaller pieces of code (preferable into small classes). This is what I aim for with my behavior tree (BT) implementation.
Another issue is the actual implementation of moving minions. Currently a minion is basically a player and the AI sends something like key events to move. On the first sight this is a very promising approach (code to move an entity is reused for players and minions) and its already working (also in my behavior branch). But it has several flaws, first of all its a bit difficult to handle, because you never know exactly, if the current move is valid, if minion get stuck into ground or movement is blocked for what reason so ever. I am not sure about moving, but what I do know is, moving of entities should be completely independent of the AI code.
To cut a long story short, some of the features from Miniions module (Moving, Animation, Pathfinding and some more) can now be found in Pathfinding Module or my behavior branch. However, the BT is not ready to be pushed into develop branch - but you can play around with it if you want.
Now the thing is, how do we continue from here? I think, we should probably rewrite/modify the Miniion module to use BT + Pathfinding. Some classes from Miniions will be replaced by newer ones, that are located in the Pathfinding module right now (Moving and Animation - maybe others too). This stuff does not really fit into Pathfinding. But that is only my humble opinion.