| Hippo's and Yellows are different families of tangs and in my experiance that cuts down on alot of issues when mixing angels or tangs. Personally, I think mixing the two angels would be more difficult simply because of the fact that they are both dwarf angels.
Now mixing a yellow and a scopas, purple, or a black would be difficult, but I dont think that there would be much aggression between a hippo and a yellow.
Nick |