Well... I'll let you know that I have a 10" Lapradei with a 10" and 8" Oscar which they don't bother at all. My 7" pacu gets chased though by the oscars.
I also have a 6" and 5" senegal with a 5", 3" oscar, 4" gt, 3" fh, 3" rd. They for the most part are left alone. I did however see my 6" senegal and my rd going at it one time after a feeding. The RD was looking at the nostrils of the senegal and took a bite at him. Both locked lips for about 1 minute and started chasing each other around the tank for another 2 minutes. Never saw any further aggression between them.
So in the end they should be fine as long as there is a difference in size/girth.