Yes, no, maybe. It usually depends on the individual fish. Your tank is too small to house two mature SA arowana, so hopefully you are considering that. If you do try the combo of the two, it is best that you have the means to separate them immediately if things go bad.
everybody says one. But how many people on here do you see with 2-3 in a 220? a lot of people keep 1 in a 100. I dont like this but hey if it works for you its your fish do what you want with them. I like the whole black and silver idea. It reminds me of the yin and yang. Do what you want with your fish its your money your time and your hobby, but Id recommend at least a 300 for 2. Footprint is what matters and water params just need to be watched carefully like any other tank.
Yes, it might work.
Now I have the silver + black aros comm tank as well.
But my case is 2 blacks + 1 silver.
They are 2 blacks, 1 silver, 2 golden severums, 2 uarus and 2 peacock basses in this tank.
But it would be like what Bderick67 had said, every fish got it's own individual characteristic. Success or not it will depend...better prepare a extra tank for any emergency happen.
For me, i would recommend not go for 2 aros comm...better go with 3 or more aros comm.