messed up with character controller, collider and rigid body

Situation: I have a character, a cube with legs made in blender and imported into unity. I made a prefab of it and duplicated it via script multiple times. Now I want to make it move with a walk animation created in blender on a spinning dice. What I achived so far: I added a capsule collider to the object and a rigid body. the cubes fall down to the platform, stay there and walk in place (but don't move). Now I read that I need a Character Controller to use some prebuilt functions that make the object move according to the walk cycle animation. Here the problems start: If I use a Character Controller (+ rigidbody) instead of a collider, the cubes don't fall down (they start at a height of 20 above the dice). I can't add an extra collider because the controller is already a collider as i read.

Then I tried something different: added box colliders to the cube the feet bones of the object an adjusted them to cover these mesh parts, also added rigid bodies to these parts and colliders - didn't work as i expected. But i consider it a cool Idea, because the feet would make the character move without any other scripting (that's at least what i hoped for :)))

Now I have no other idea what combination of physics object i need to apply on which part of the blender object to gain the expected result.

Any help? Thanks in advance