They'll probably be fine with sharing once they know each other (and you know how they react) well enough. We got very lucky with Millie & Chester. Never had a single incedent over a toy, and bones only once or twice. Like Aly said, have a lot of toys handy. We have close to 60 in various states of disrepair.

I would make sure that Lucy & Ray still both have chewing time apart from each other. They need to be able to get those frustrations out.