Many people keep different species of parrots in the same cage.
There is no way to know if they would get along though. You
need to take it slow and easy introducing them to each other.
Our Yellow Nape (male) and Double Yellow Head (female) use to
have their cages side by side. Sometimes they would sit next to
each other in one cage or the other. When the Nape wanted
attention he would do something to scare the DYH ( which doesn't
take much) so we would come running. He never tried to hurt her
but it doesn't take much to scare her either. That is why her
nickname is "Poopsee", because if you scare her she will Poop See.
We finally went ahead and separated their cages after the Nape
sneezed, the DYH was asleep and it scared her. She flew off the
cage and somehow manages to cut her toe. Rush to vet followed,
it wasn't a bad cut. She did look really cute with a bright
yellow vet wrap on her toe. The vet use yellow to match her
head. She never messed with it either.
Now their cages are about 3 feet apart. The DYH still scares
easy just like her mom (me). They get along but we just don't
keep their cages together any longer.