You want the daggerboard CoE (Center of Effort) to balance the sailplan CoE. With the A-cat, which has only one sail, they can put the daggerboard further aft. F-16s need to consider the spi and jib sailarea, so the daggers are a bit further forward.
Then some designers start to spread the load generated by the sails between the daggers and rudders, either by mast rake or by daggerboard placement. There are written whole books on this subject, Marchaj has written what I think is the definitive work: http://www.amazon.co.uk/Aero-Hydrodynami...TF8&s=books