To reduce the chance of different computers all trying to access the same tuner, you can try ordering the tuners differently on different computers. For example, you can order the tuners 1, 2, 3 computer 1, but 2, 3, 1 on computer 2, and 3, 1, 2, on computer 3. This way they will each use a different tuner, unless some of them need to use multiple tuners at once.