I highly doubt the fronts will beat up the Arowana, they are very peacefull fish. I am sure they will be fine, just keep an eye on everyone else in the tank. Make sure that your fronts have alot of hiding places. I am sure they'll be fine I ve kept 3 Fronts with a datnoid, two clown knifes and 2 Arowanas and the Fronts have been the least agressive and hide alot. Although I dont think your going to enjoy your fronts that much, they do best with themeselves in colonys, thats when they are really alive and out and look beautiful and dont have stress. I would keep them alone but then again some mfk people have done fine w/keeping them with other fish. Well thats just my input, good luck with it, cant wait to see pics when its done!