9-11 tats is a bad idea. As juveniles they will be fine together, although once they hit maturity the aggression issues will start. Once Payara species hit maturity they tend to become solo predators. You would need tons of decorations to break up each fishes line of sight so they have a sense of security. Your best bet would be 3 tats, 1 alpha to 2 submissive, along with other dithers.
Or you could use the cash you would have spent on multiple redtail tats, and get a armatus. You may loose some of your stock though lol