Fish #1 is the dominant fish. That doesn't necessarily mean male, but usually is. Fish #2 and #3 are subdominants, possibly male on #2, but that's purely a guess. #3 is being harassed, this is the reason for the torn fins, and could be at risk from my experience. I hope the tank is large, as these fish are not the typical "dwarf" species, and are pretty bad about intraspecific aggression.
I have found a lot of confusion over thayeri and flavilabris, but I question the ID of many of the photos that are out there on these two species. The names are often assigned to collected specimens without cautious investigation first.
I had a group of 7 of these fish in 2005-06, purchased as thayeri, and only one dominant fish showed that pattern in a small tank (15 gallons) where they were held for the first 2 months. When moved to a long 30 gallon, a second fish colored up, and the two split the territory between them. One of them spawned once with a small female (eggs did not survive), the other was killed by what I had thought was another female, but it then took on dominance coloration and started harassing the other dominant fish. Not long after, I had a disaster that caused me to lose the entire tank.
I will try to post some shots of my fish later. Need to resize them first.
There are two kinds of error: blind credulity and piecemeal criticism. Sound skepticism is the necessary condition for good discernment; but piecemeal criticism is an error. - Egyptian proverb