Hi different shrimps do grow to different sizes the three you have mentioned should grow to about 3-4cm but ocasionly they do grow bigger. i recently baught two cherry shrimp and two bumble bee shrimps. I asked the fish shop why one of the cherrys were so big and he said it can depend on the quality off the tank they have growwn up in. I dont think you should worry about your fish eatting them. But when putting the shrimps in i would watch the fish at thirst to monitor there behaviour. Let me know how it goes... Alex hope the info helps
It is good and gives the growth sizes of each shrimp....but i wonder if the smaller ones will become food....i guess it all depends on how big the mouths of my Rams are when they arrive haha