3 will still fight. I bought 2 and they constantly faught when I put a third in it was fine for a month now I have one that is beaten up. They constantly fight with each other and gang up on the beaten one. If I was you sell two and keep one. Unless u have a ginormous tank
I had 5 and they worked very well together... too well in fact...the group had a thing for killing tinfoil barbs over twice their size. So I sold 4 to a vendor in Pittsburgh.
Do explore the possibility of getting one that has done well in comm tanks or perhaps going to the LFS to pick a mild manner specimen (daunting task but worthwhile).
Here is my dorado that is behaving well so far - got him from a hobbyist who assured me this guy is not a killer.
Red, your dorado looks like a spitting image of mine. Around 13-14" right? Mine is probably the smartest, fastest and most brutal of all my monster fish. I don't even think my aimara wants anything to do with him as he doesn't even lunge at the dorado behind the divider anymore. The dorado pin pointed the aimaras weakness behind his eyes and speed. I have a buddy here that had a tank full of large dorados at around 20" but he got rid of all but one as they couldn't be kept with anything else but catfish and stingrays.
Completely agreed with the bad traits you mentioned as well. LOL!
I had kept a couple of bad tempered ones and with their speed and mass - no fish is really safe once they set their sights on it.
Would say perhaps 80 percent of Dorados sold by hobbyists are due to their aggression. But with patience - I believe one can hit on a great specimen with good temperament.
In fact, one of my Facebook contacts had one posted (about 17 inches) for sale a couple of days ago and his was badly beaten up by an aro. These are the opportunities I wouldn't miss if I had not gotten one already.