At least the one in the third picture seems to be real sumatranus. You can even see the red band in it’s dorsal fin. They’re from the same batch as mine, which undoubtedly are the real deal.
My sumatranus didn’t have the filament in the beginning, and even now it’s not always clearly visible in all indivuals. Some even seem to lack it completely. Their courtship dance is head up, so they really are sumatranus.
I don’t yet exclude the possibility of them being sumatranus. Wait until they show their true colour.