The bottom line is Angels are cichlids. If it fits, it's lunch.
But I have to ask a couple of questions here:
Have you actually caught the Angels "in the act"?
Smaller specimens of fish like neons and threadfins can be delicate at best. How are the rest of what didn't cut it with the angels doing?
Angels can be singular in behavior as well. Meaning an individual can just have a mean streak in him. But I have to say, I'm pretty surprised about the cherry barbs unless they were neon-sized.
I have a bunch of angels in 40B that are sub-adults. Big, but not huge and just about pairing-off age. All of a sudden one day one bugger decided the whole tank was his and all the rest were simply cowering along the walls of the tank. So he was quickly removed and sent off to live with the big guys. I also have a 180G with my biggest and oldest retirees. Aside from a display tank, I also use it as a penitentiary for delinquents like him. They straighten up real fast in there.
I've usually got a place to put misfits and aggressive angels at any given point. In your case, you may want to consider one tank a true display that's going to have the color and diversity you're looking for and the other simply a home for the angels and something else that can hold its' own if these guys are in fact chowing down on small fish.
I've seen only one chase the rummynose tetras, the koi one is way more aggressive, while my wild one really doesn't care what's in the tank.
I moved out all the tetras and threadfins and barbs into my 30g with my kribs so they're fine now
I was pretty surprised too about the cherrybarbs because were a pretty good size and stayed on a different level than my angels, i did see that one was struggling to swim and the koi angel was following it and attacked from the bottom, i removed him but he didn't make it
I would love to get atleast 2 more angels but I'm afraid they'll pair off and completely massacre, the ones I have right now are either 2 males, 2 females or not into each other at all