The lutino out grew the tiger probably because he's more aggressive during feeding time and had to move the tiger to a grow-out tank so he can catch up. Unfortunately there was a powerhead accident on the grow-out tank and the tiger got sucked and stuck.
I also tried to introduce a Red Oscar 3/4 of his size. That oscar was so timid and wouldn't defend himself or at least get out of his way. I've tried moving/removing decors and sand so that both oscars would start off on a newly "reset" tank. After I've placed them back in the tank they seem not to mind each other so I went out. When I came back home I found the Red Oscar dead.
The lutino was staring at me like a seasoned Mafia hitman. He was like saying, "Introducing a new fish huh? I don't think so."
Hence the name "The Boss".