You've already been reminded not to make multiple threads for same issue. There is no need to start another thread. You are actually better off asking image questions in the image support question.
Services become available to tuners that are compatible with them. You do not assign services to tuners. The image decides what to use based on what is going on/being requested. You can set the preferances, it takes these into account. If you do not want to use the motorsied dish for the 28.2 services, you can set the dish to "Positioner selecting satellites". Do not enable 28.2. That tuner then becomes unable to receive 28.2 services and receiver will not try to use it for 28.2 services.
If you have four tuners, they are independent. The only time that this would nt apply would be if you had a multi port LNB and also had a cable direct from LNB to tuner, by passing the motor.