My daughter has three sisters in one tank together, only minor pecking order at dinner time; they keep company with three oto cats.
But she has another so aggressive it recently jumped from one tank to another and killed all the residents she could reach. Shw was preventeedd from being oscar chow with a former owner by us. But she has really tron thorugh his community tank before she was stuck in amargerine tub til we got her.
She killed 4 young angels, 2 gourami, one of her 3 sisters, 5 otos 2 cories and surprisingly a dwarf cichlid. All in a span of 3 days. And they had to nearly tear down the tank to catch her and remove her.
So there are some extremes for you.
Just be careful and make sure that the lesser fish can escape the dominant one.
watch closely for signs of major aggression.
Also they are more likely to fight harder if they are equally matched than if there is differences in size. If they are on teh aggressive side, ,that is. If they all came from the same tank you are less likely to have problems