I tried that, initially, but things just got worse despite trying to give them more "safe" spots. I didn't want to lose them so they had to move out. I have quite a lot of driftwood in my 55 and lots of plants and plenty of hiding places, but the bully angels would seek them out and make them go back to the corner with the filter intake (which has always seemed to be everyone's least favorite place in the tank, except for my smallest BN pleco who likes to chill out between the tube and tank wall) and they woudln't come up to eat, and even if I dropped bloodworms near them they acted like they were afraid to move at all. They are eating fine now, but like I said it took them a few days to touch anything once they were moved.
I am absolutely fine with just having the two angels in my 55 - that's all I really wanted, but I got mine on ebay and initially had 9, and gave some away, thinking I'd keep the 4, but they had other ideas.