I only use MPC in Bonded Contact, so I have nothing to say about using MPC formulation in Frictional Contact, but you can read this section of Ansys Help to learn more about MPC contact.
Don't use MPC contact between RIgid Bodies. See this info in the Ansys Help:
Normal Lagrange uses the Lagrange Multiplier method.
Now, instead of just the deformation of nodes being the unknowns in the matrix equation, there are a number of Lagrange multipliers included in the matrix equation, which now includes a constraint that the penetration must be exactly zero. The solver iterates on the value of the Lagrange multipliers that enforce the zero penetration. This is completely different to the Penalty-based method you know about that has a Normal Stiffness to multiply with the Penetration to compute a contact Force and iterates on nodal position alone to find equlibrium.
Program Controlled frictional contact uses the augmented Lagrange Penalty-based method. Read about the pros and cons of each in this section of the help.