There are absolutely no guarantees with this combo, anyone who will make one doesn't know much about fish. Angels and Neons sometimes works but not always. There is no absolute fool proof way to guarantee that you will not loose any Neons because every fish is different and has it's own personality. Sometimes it works to have the Neons in the tank for a while before adding a small Angel, and by small I mean quarter-sized, and even then it doesn't always work. Neons are a natural food for Angels in the wild so you are trying to get predator and prey to live together, thus there are no guarantees. So it really boils down to the question of weather or not you are willing to try it, nobody can tell you definitively yes or no on this one.