Getting two pairs of linnies in one cage
I have 4 linoleated parakeets in two cages, all of around the same age with the oldest being 6 months and the youngest 3 months. The 2 oldest and the youngest one are female, and the 3rd (second youngest) is male. The older two are a pair, and the younger two are a pair.
I have a large enough cage for all four, but they don’t tolerate each other. They always want to go to each others cages and explore, and seek out one another, but it always (almost immediately) ends up in fighting until one is chased off completely. There is no breeding spots, and I have zero desire to breed with them. They are all more or less tame, they are living room birds. There is enough food and water available and plenty space.
The fighting has gone on for over a month, during which time the two cages have been placed next to each other.
Is there anything I can do so they will flourish together in one cage?
Should I break up the pairs and get them to bond with one of the other? That seems really sad to me, idk I’m invested in their relationships.
I’ve tried having them swap cages for a day, putting 3 in the same cage and the oldest (who seems to be the most involved in starting fights).
Sorry, it’s a short question but with a lot of context.