fish will try and eat anything that will fit in their mouth may it be an angel, discus, ram, platy etc etc angels get big and so do their mouths. dwarf shrimp like cherries stay small so when discovered by the fish will become lunch even in a well planted tank its only a matter of time...... my 2 large angels munched through almost 50 cherry shrimp in a planted tank within a week the only ones left were 4 amanos and smaller cherrys that got sucked into the filter!
angels also eat neons in the wild as do discus so mixing them is a gamble too, they are not BAD fish they are just higher up in the food chain than neons, shrimp etc etc..... its advised that if you are to add smaller tetra type fish with angels then go for fuller bodied ones like serpae, black skirt etc etc as the angel doesnt see them as eatable where as a small thin torpedo shape fish fits nicely into the angels mouth and most of the time eventually does.
by all means try the shrimp but im 99.9% sure it will be a waste of your cash