Help in postioning urgenttt

[balahh]

Initially, I suffer from this comment “ set a wise plan, the players don’t know what to do”
Does it means that my players should be from same nation or continent or same league ?

Also , I have a question about the chemistry
Is it better to put a CAM player in his exact position or it won’t be different from any other midfielders’s positions??
answer last question for each field