Made a thread about this today.

You will never see any combination of MC with anything else unless the previous player has specifically spent 50 skill points on training that position to him. The same goes for ST.
You can realistically see all other combinations of adjecent positions. Common are: DC/DR, DC/DMC, DC/DL, DMR/DR, DML/DL, MR/AMR, ML/AML, AML/AMC and AMR/AMC.