lake kyoga flame backs and rubys run a greater risk of hybridization because the color pattern is similuare. when mixing victorians its a good idea to have complete oppisit appearances.
a good mix is something like the diffrent nyereri species with verticle bars, and maybe fulu that has horizontal bars.
i also have had good luck with species where the body is a solid color like the mbipia mbipi with one with bars verticle, like astotatilipia latificinata.
i have seen mbuna hybridize and peacocks so if your idea is to spawn and sell pure species unless you wittnes the spawn id grow them out to make shure they are pure.
also look at the females alot of females victorians look very similure so make shure they are diffent as well.
here are a few examples of species i have kept togather in my own tanks.
see how the rubys and the kyoga have a rather similuare color pattern, not a good choice for mixing
ruby green
kyoga flame back
here is an example of a good mix
mbipia mbipi, haplochromis copper black
and paralibidochromis sp mwanza rock rock krib
another good mix is nyereri species like this and klake kyoga "obliquedens" astotatilipia latificinata
astatotilipia latificinata
another decent choice can be
ptyochromis sp salmon
and the xystichromis phytophagus, or christmas fulu
here is an example from my own takns of an all male mix. quite abit of agression.
i hope this was helpfull.