ok....flowerhorns have the pitbull stigma around them..... i own 5 red dragons or ZZ's... a m/f pair live in one 75g central american cichlid community tank... i have never had a problem ... they even spawnd last week and were still fine in there... they are about 6-7" maybe 8" at the moment...they do fine...infact they get beat up by convicts when they are spawning there are also rainbow, severum, parrots, firemouths....all of these are smaller with the acception of the large male cons that are just about half inch smaller than the famales.... and the full grown parrots
in my second tank i have a large female, a large unknown sex/ type, and 2 juvies.... they live great with cons, jd, gt, tex, parrot, salvini,.....all of which are smaller!!!
never have they hurt any of the other fish or themselves....
what i would recomend is keeping them in a community tank form the day you get them!!! place them with hardy cichlids of the dame size(convicts work great) so they can get use to the company...even if you go buy cons for this one purpose it will benifit you in the end if you want an amazing tank with diversity!!!! and def allow for some hiding places!!!!
i think the issue people have is buying a flowerhorn that is use to being alone and cant adjust to the company of other fish, even if it is a female of the same speicies....