I started out with four oscars all 2" long and within a month my two albinos killed my two tigers. One of the albinos grew to 4" and the other about 3" when I bought my other tiger. He was only 2" and got picked on but ate a lot and grew extremely fast in fact he is now about 4 1/2" the albino is 5" and the oher albino is about 3 1/2" so he is the 2nd largest in my tank. Up until yesterday I would see them chase each other but never cause any damage but when I got home from work the tiger was missing part of his fin that goes along his back which I know happens so I didn't think much of it. I always watch them a while before I feed them and I noticed the largest albino picking up rocks from one corner of the tank and spitting them out in the other. I watched this for a few minutes fed them and went to eat when I returned the albino was gaurding this 'nest' he created in the gravel and even my pleco got a lashing when he swam near this hole. I fed them again and turned out the light and from my bed I could see them taking turns laying in the hole then all 3 of them were laying in the hole and today the hole was gone and there was no aggression. There is no real problem or question here it was just strange to me so I decided to write about it.

Lol, I sure would love to know at times what is going on in their heads, reminds me of little kids in a sandbox
Hope they will all get along - if two pack up or even pair up, you might just end up having to remove the odd one, but bet you know that yourself. Good luck, it never gets boring with Oscars.