I found the cherubs to be more predictable than the flamebacks. When you get a mean flameback they are MEAN but a ‘bad’ cherub usually has a problem with a specific fish in a specific area for like a week. In my case, the cherub HATED one of my clowns being in a duncan and I have no idea why. They fought for about a week, some chasing and a little bit of torn fins was the extent of the damage. I guess maybe after a week the cherub just kinda gave up and realized that the clown wasn’t gonna move and he had to deal with it?
Out of the 5-6 cherubs I’ve ever had (or that my dad has had, I just asked him this as well) my current one is the most aggressive and the above event is the reason. I’ve never had one pick on corals or chase EVERY fish in the tank. It’s always just been one fish, in a very particular area that ticks the cherub off. I have my other clown in a hammer not even 3” away from the duncan and the cherub doesn’t care about that clown and it doesn’t care about the duncan clown if it’s away from the duncan.
So, by all means, I suggest trying a cherub. A 60 cube should be way more than enough territory for one to establish its little area and to be happy and a good tank mate. You’ll find that they are actually very curious and that they actually like to seek out activities to to to have fun! I have a small pile of rubble in the back of the tank just to build weird arches and stuff so I can watch the cherub gleefully swim through all the arches and holes and things. He has found the tiniest gaps in the rock work to wiggle through and I swear he looks proud when he finds a new hole. They’re really awesome fish and ,as you experienced, they have very pronounced personalities if you take the time to get to know them. I wish you the best of luck with your cherub!