three tv series, one universe

i spent my entire childhood watching the German police series "Alarm fur cobra 11", and once, in the episode "highway maniac" I heard firstly the song "keep hope alive", and when I googled the song, i stumbled to similar series "third watch", but i loved c11 as much, as I wasn't needed by something similar, but one day, I founded and saw another German action series "GSG 9", which had the same dub actors, as c11, so I was looking for something another, as German too, as with the same dub, and when I entered on the page, where the channel, who dubbed C11 and GSG 9, was making a list of the series, he recommends, the one of them was another German action series, from c11 creators "Medicopter 117", I immediately copied the name, and started to watch, this series impressed me as much, as it was harder for me to rewatch C11 after that, and when I little tired from 117, I remembered about "Third Watch", and started to watch it too, and after I decided to make a crossover between all three TV series, the events of my story will happen, as before, as while and as after the basic events of these three series.