They prefer to be in flocks, but they have different grouping behaviors than chickens. Left to their own devices, with the exception of mating season, males of different ages form a separate group from the hens. The hens and younger birds, including juvenile males, will hang together.
For the few that you want, they'll be okay together. I have one tom and two hens. They don't necessarily "flock", but have their territory in the backyard that they share with some chickens. They mingle around and are aware of each other's presence, but don't stick close to each other like chickens do. They do roost together at night, though.
Stacey