yer its always better to have a bigger colony but i would go for at most 3 m not 8 and 12 is a very good number of females, but basically with fronts u want as many females as u can and keep usually upto 3m and sell of the other males
I would go with only 2 males (a alpha and beta male) the rest of your large colony should be females. The alpha and beta males would likely just shred or kill other less dominant males and that constant fighting would cause a very stressed out non breeding tank . Thats just my opinion anyway. Frontosa are harem breeders, the more females the better as long as your tank is big enough to house them all as adults.