yeah as long as they have some time to grow out and get ahead of the O then it shouldnt be an issue, but yeah like others said you will barely every see the raphaels though, why dont you get a nice shoal of pictus or something, they are active and will all swim around together. also as far as i know the spotted raphaels dont get as big so if you go with the raphael make sure it is the striped kind since once an O if full grown it could try to eat the spotted and would probably choke on the spines...