A fuzzy wouldn't eat an adult maroon. Those fish are bigger than he is.
But here's the thing. Fish are not meeting their real potential size if we are growing them in our systems. If I bought a small maroon and grew him for a year, I guarantee you if I caught a 1 year old from the wild, he'll be bigger. So, if I'm looking to make a mix, like a perc and a fuzzy. I would make sure to look for, and wait for, a really big adult perc.
I've seen percs come in that a fuzzy would not eat, but I can't make a blanket statement and say they are all safe with dwarfs. Smaller fish do not always reach their full size potential if they are captive raised.
Does that make sense? Am I coming across okay on that?