They both have the same parentage...Rothkirch X Ocre.
They were both hybridized by the same person, Mrs Blin in Germany so could well have been seeds from the same seed pod perhaps. Just having the same parents would make them look similar to most eyes.
Now that there is a Brugmansia Registry a person has to fill out many questions on leaf shape, bloom size and shape, bug resistance and another things that would help people to ID one similar flowering Brug form another.

I agree with RA on this but there is also some that give them the incorrect name as they try to ID from photos and this has been a long going problem when folks want to name a brug without the proper DNA testing.