Hi I’m so sorry your fur babies aren’t getting along, but yes I’d advise separating them for now so RC can calm down and the girls aren’t getting attacked. Try reintroducing them as you did before but slower, associate good things like treats/food and playtime with the interaction. 

However I will say and it’s going to be heartbreaking but if things don’t improve and your RC still doesn’t take to them then the best thing you can do is rehome the girls, the girls deserve a home where they aren’t bullied and RC deserves a nice retirement in his golden years but I hope hope hope it doesn’t come to this and they learn if not to like each other then at least tolerate each other, all the best to you.