In Arch Linux trying to use Dual T.16000M flightsticks, the problem is that they are both trying to use the same name/address and only the last one to load exists. The other flight stick becomes invisible to the programs looking for them. If one of the flightsticks is swapped out for different brand then both are detected properly.
The problem also affects udev which has both flightsticks overwriting the same /dev/input/by id/ symlink.
Bug report for the affected software including udev data for the flightsticks;
Me trying to make sense of the bug in the Arch Linux Newb Corner, also includes the udev data.