Theyll probably say to keep them in an aviary.
I also dont think its much to do with clashing, i think its quite rare although it can happen. Take a look at the race programme in the BHW and see how many liberations take place on a saturday, even if some cross paths, the chances of them occupying the same air space at the same time is low compared to the size of the country and distance they are covering. Just my thinking anyway