i have kept a 7-8" O with a 5" male flame FH and a 6" female flame FH along with 5x 4-6" cubans , a 7" GT 3x 4-5" jags
haven't seen any torn fins till now and the O is the high command and the gt is the right hand man of the O
i have seen someone keeping a pair of adult Os along with an adult FH and a 9" GT