When putting a male and female cichlid together, there is almost always a 50/50 chance one will end up dead. Consider if you were just stuck in a tiny room with Ralph, or me, and no alternative. Before I ended up divorced, I slept wit one eye open.
Putting cichlids in a tank that is divided, giving time to get acquainted before removing the divider, , there is a slightly better outcome possibility.
In my tanks, to get a pair, or a compatible group, i usually get 8-10 juvies, and raise them together. Most of the time a few are lost in the juxtaposition for power in the hierarchy, but I consider this simply, reasonable collateral damage. It has worked well, and often a pair that gets together of their own accord, seem to have a much better, and lasting bond.
But as alluded to by LBDave, tank size can be the most important limiting factor.
I have watched a small pair of JDs in nature defend an area of about 250 gallons square.
Check out the young pair at the one minute mark in the video below. They chase away any other cichlid except its mate, but allow non-competitive dither fish free reign.
Cristalino
With so much space to flee, there is seldom damage, but few tanks even come close in having enough space to avoid death or serious injury.