If there are three models in the scene with different friction coefficients, which friction coefficient will be used by the physics. I use same value for both mu and mu2.
ground plane: 100 | box: 0.5 | finger: 500

Before finger touching the box: According to the documentation, it will be min(100,0.5) --> 0.5
After finger touching the box: it will be min(100,0.5,500) --> 0.5

When then three models are in contact while sliding(translating the hand), somehow the finger slide faster than the box. How do I set the friction coefficient such that the object stays under the finger, when the hand is translated. I tried tweaking kp, but that did not help.

box kp=3.5e6, max_vel=0.01